Image forming apparatus

Abstract

This prevents damage to components or malfunctions caused by interference between components constituting the positioning and fixing mechanism when the opening and closing mechanism is closed. [Solution] Of the pair of resist rolls 54, one conveyor roll 54a is mounted on the device body 1a so that the tilt of its rotation axis can be adjusted by a tilt adjustment means 70, and the other conveyor roll 54b is mounted on an open / close cover 110 which is attached to the device body 1a so as to be openable and closable. When the open / close cover 110 is closed, the other conveyor roll 54b is fixed in a position relative to the one conveyor roll 54a by a positioning fixing means 80. At this time, the positioning fixing means 80 is configured to position the other conveyor roll 54b in accordance with the tilt of the rotation axis of the one conveyor roll 54a by the tilt adjustment means 70.

Description

Technical Field

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[0001] This invention relates to an image forming apparatus.

Background Art

[0002] Conventionally, as a technology related to an image forming apparatus, for example, those disclosed in Patent Document 1 and the like have already been proposed.

[0003] Patent Document 1 is configured such that when the opening / closing door is opened, the timing of the peak of the operating force exerted by the transfer positioning member on the opening / closing door is different from the timing of the peak of the operating force exerted by the roller positioning member on the opening / closing door.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] An object of this invention is to suppress the occurrence of damage to members or malfunction due to interference between members constituting the positioning and fixing means when the opening / closing means is closed, as compared with the case where the positioning and fixing means for positioning and fixing the other conveyance roll attached to the opening / closing means among the pair of conveyance rolls does not correspond to the movement of the other conveyance roll along the adjustment direction of the inclination adjustment means.

Means for Solving the Problems

[0006] The invention according to claim 1 includes an opening / closing means that is detachably attached to the apparatus main body, a transfer means provided in the opening / closing means for transferring an image from an image holding means to a recording medium at a transfer position, a pair of conveyance rolls for conveying the recording medium to the transfer position, An inclination adjustment means for adjusting the inclination of one of the conveying rolls of the conveying roll pair that is mounted on the main body of the device, A means for positioning and fixing the other conveyor roll of the conveyor roll pair, which is movably mounted on the opening / closing means, to the device body before the transfer means comes into contact with the image holding means when the opening / closing means is closed, the positioning and fixing means allows the other conveyor roll to move along the adjustment direction of the tilt adjustment means and restricts the position of the other conveyor roll when it moves to the end on the device body side, This is an image forming apparatus equipped with [a specific feature].

[0007] The invention described in claim 2 is characterized in that the positioning and fixing means is provided on the opening and closing means and holds the other transport roll so as to be movable between a temporary holding position and a transport position while allowing movement along the adjustment direction of the tilt adjustment means, The device body is provided with fixing means for positioning and fixing the other conveying roll to the conveying position, The image forming apparatus according to claim 1, comprising:

[0008] The invention described in claim 3 is an image forming apparatus according to claim 2, wherein the holding means is a movable mechanism comprising a regulating member for regulating the position of the other conveying roll, an elongated hole into which the regulating member is fitted, and a biasing member for biasing the regulating member toward the apparatus body, thereby movably holding the other conveying roll.

[0009] The invention described in claim 4 is an image forming apparatus according to claim 3, wherein the holding means holds the other conveyor roll so that it can move along the adjustment direction of the tilt adjustment means by setting the opening width of the elongated hole in a direction intersecting the movement direction of the other conveyor roll to be wider than that of the regulating member.

[0010] The invention described in claim 5 is an image forming apparatus according to claim 3, wherein the holding means restricts the position of the regulating member when it moves to the end of the elongated hole on the device body side, thereby restricting the position of the other conveying roll when it moves to the end on the device body side.

[0011] The invention described in claim 6 is an image forming apparatus according to claim 3, wherein the fixing means comprises a positioning member provided on the apparatus body side and having a first recess into which the restricting member is fitted, and a fixing member having a second recess that engages with the restricting member to fix the restricting member in the first recess.

[0012] The invention described in claim 7 is an image forming apparatus according to claim 6, wherein the second recess of the fixing member is opened in a direction intersecting the opening direction of the first recess.

[0013] The invention described in claim 8 is an image forming apparatus according to claim 6, wherein the fixing member comprises a fixing arm member that is rotatably provided on a holder that holds one of the transport rolls, with respect to a rotation center.

[0014] The invention described in claim 9 is an image forming apparatus according to claim 8, wherein the second recess of the fixed arm member has an engagement surface with the regulating member formed in an arc shape centered on the rotation center. [Effects of the Invention]

[0015] According to the invention described in claim 1, compared to a case where the positioning and fixing means for positioning and fixing the other conveyor roll of the conveyor roll pair, which is attached to the opening and closing means, to the main body of the device does not correspond to the movement of the other conveyor roll along the adjustment direction of the tilt adjustment means, it is possible to suppress damage to the components or malfunctions caused by interference between the components constituting the positioning and fixing means when the opening and closing means is closed.

[0016] According to the invention described in claim 2, the positioning and fixing means can suppress interference between the members constituting the positioning and fixing means, which can lead to damage to the members or malfunctions, compared to a case where the other transport roll is not allowed to move along the adjustment direction of the tilt adjustment means.

[0017] According to the invention described in claim 3, the holding means can simplify the configuration of the movable mechanism as compared with the case where the other conveying roll is movably held by a link mechanism or the like.

[0018] According to the invention described in claim 4, the holding means can suppress the occurrence of damage or malfunction of the member with a simple configuration as compared with the case where the opening width of the long hole is equal to that of the regulating member.

[0019] According to the invention described in claim 5, the holding means can surely position the regulating member on the apparatus main body side as compared with the case where the position of the regulating member moved to the end on the apparatus main body side of the long hole is not regulated.

[0020] According to the invention described in claim 6, the fixing means can surely position and fix the regulating member as compared with the case where it includes only the positioning member provided on the apparatus main body side and provided with the first recess into which the regulating member is fitted.

[0021] According to the invention described in claim 7, the second recess of the fixing member can surely fix the regulating member by the second recess as compared with the case where the first recess is opened in the same direction as the opening direction.

[0022] According to the invention described in claim 8, the fixing member can easily cross the opening directions of the second recess and the first recess as compared with the case where it is not composed of the fixed arm member rotatably provided about the rotation center on the holding body that holds one of the conveying rolls.

[0023] According to the invention described in claim 9, the second recess of the fixed arm member can maintain the contact force with the other conveying roll constant even when the position of one of the conveying rolls fluctuates as compared with the case where the engagement surface with the regulating member is formed linearly.

Brief Description of the Drawings

[0024] [Figure 1]This is an overall configuration diagram showing an image forming apparatus according to Embodiment 1 of the present invention. [Figure 2] This is a perspective view diagram showing an intermediate transfer unit of an image forming apparatus according to Embodiment 1 of the present invention. [Figure 3] This is a diagram showing the main components of an image forming apparatus according to Embodiment 1 of the present invention, with the side cover open. [Figure 4] This is a perspective view diagram showing the side cover. [Figure 5] This is a configuration diagram showing the main parts of an image forming apparatus according to Embodiment 1 of the present invention. [Figure 6] This is a configuration diagram showing the main parts of an image forming apparatus according to Embodiment 1 of the present invention. [Figure 7] This is a perspective view diagram showing the main components of an image forming apparatus according to Embodiment 1 of the present invention. [Figure 8] This is a perspective view diagram showing the tilt adjustment member. [Figure 9] This is a configuration diagram showing the main parts of an image forming apparatus according to Embodiment 1 of the present invention. [Figure 10] This is a configuration diagram showing the main parts of an image forming apparatus according to Embodiment 2 of the present invention. [Modes for carrying out the invention]

[0025] Embodiments of this invention will be described below with reference to the drawings.

[0026] [Embodiment 1] Figure 1 is a schematic diagram showing the overall configuration of an image forming apparatus according to Embodiment 1. In the figure, arrow X indicates the horizontal direction of the image forming apparatus, Y indicates the depth direction of the image forming apparatus, and Z indicates the vertical direction of the image forming apparatus.

[0027] <Overall configuration of the image forming apparatus> The image forming apparatus 1 is configured, for example, as a color printer. As shown in Figure 1, the image forming apparatus 1 includes a plurality of image forming devices 10, an intermediate transfer device 20, a secondary transfer device 30, a paper feed device 50, a fixing device 40, etc. The plurality of image forming devices 10 form toner images that are developed with toner constituting the developer. The intermediate transfer device 20 holds the toner images formed by each image forming device 10 and transports them to a secondary transfer position T2 where they are ultimately transferred to recording paper 5, which is an example of a recording medium. At the secondary transfer position T2, the secondary transfer device 30 transfers the toner images transported by the intermediate transfer device 20 to the recording paper 5. The paper feed device 50 collects and transports the required amount of recording paper 5 to be supplied to the secondary transfer position T2 of the intermediate transfer device 20. The fixing device 40 fixes the toner images on the recording paper 5 that have been transferred by the secondary transfer device 30. Reference numeral 1a indicates the main body of the apparatus, which is formed by support structural members, outer covers, etc.

[0028] The imaging device 10 consists of four imaging devices 10Y, 10M, 10C, and 10K, each dedicated to forming toner images of four colors: yellow (Y), magenta (M), cyan (C), and black (K). These four imaging devices 10 (Y, M, C, K) are arranged in a single row within the internal space of the device body 1a, tilted with respect to the horizontal direction X.

[0029] Each imaging device 10 (Y, M, C, K) is equipped with a photoreceptor drum 11 that rotates along the direction of arrow A, as shown in Figure 1. Around this photoreceptor drum 11 are a charging device 12, an exposure device 13, a developing device 14, a primary transfer device 15, a drum cleaning device 16, etc. The charging device 12 consists of a charging roll that charges the image-forming surface (image-holding surface) of the photoreceptor drum 11 to the required potential. The charging device 12 has a cleaning roll 121 for cleaning its surface. The exposure device 13 irradiates the charged surface of the photoreceptor drum 11 with light based on image information (signals) to form electrostatic latent images (for each color) with potential differences. The developing device 14 develops the electrostatic latent images with toners of the corresponding color (Y, M, C, K) to form toner images. The primary transfer device 15 transfers each of these toner images to an intermediate transfer device 20. The drum cleaning device 16 cleans the image-holding surface of the photoreceptor drum 11 by removing any toner or other deposits that remain after the primary transfer.

[0030] Each developing device 14 (Y, M, C, K) is constructed by arranging a developing roll 141, agitation and conveying members 142, 143, and a layer thickness regulating member 144 inside a housing 140. The housing 140 has an opening and a container for the developer. The developing roll 141 holds the developer and conveys it to the developing area facing the photoreceptor drum 11. The agitation and conveying members 142, 143 consist of screw augers, etc., that convey the developer while agitating it as it passes through the developing roll 141. The layer thickness regulating member 144 regulates the amount of developer (layer thickness) held by the developing roll 141. The four color developers (Y, M, C, K) used are two-component developers containing non-magnetic toner and magnetic carriers.

[0031] Each developing unit 14 (Y, M, C, K) is supplied with toner of the corresponding color from yellow (Y), magenta (M), cyan (C), and black (K) toner cartridges 145 (Y, M, C, K) located above the intermediate transfer unit 20, via a toner supply device (not shown).

[0032] The primary transfer device 15 is a contact-type transfer device equipped with a primary transfer roll that rotates in contact with the circumferential surface of the photoreceptor drum 11 via an intermediate transfer belt 21 at the primary transfer position T1, and to which a primary transfer voltage is supplied. As the primary transfer voltage, a DC voltage or current exhibiting the opposite polarity to the charging polarity of the toner is supplied from a high-voltage power supply.

[0033] The drum cleaning device 16 consists of a cleaning blade 161 and a delivery member 162, which are arranged inside a container-shaped main body 160. The cleaning blade 161 cleans by removing residual toner and other attached substances. The delivery member 162 collects the toner and other attached substances removed by the cleaning blade 161 and transports them to a collection system (not shown).

[0034] The intermediate transfer device 20 is positioned above each imaging device 10 (Y, M, C, K). This intermediate transfer device 20 mainly consists of an intermediate transfer belt 21, a plurality of belt support rolls 22-25, and a belt cleaning device 26. The intermediate transfer belt 21 moves in a circular motion in the direction indicated by arrow B, passing through the primary transfer position T1, which is between the photoreceptor drum 11 and the primary transfer device 15 (primary transfer roll). The plurality of belt support rolls 22-25 support the intermediate transfer belt 21 from its inner circumference, holding it in a desired state and allowing it to move. The belt cleaning device 26 cleans the intermediate transfer belt 21 by removing any toner, paper dust, and other deposits that remain and adhere to its outer surface after passing through the secondary transfer device 30.

[0035] The belt support roll 22 is configured as a drive roll. The belt support roll 23 is configured as a surface-setting roll that holds the running position of the intermediate transfer belt 21. The belt support roll 24 is configured as a sensor roll facing a sensor (not shown). The belt support roll 25 is configured as a backup roll for the secondary transfer device 30.

[0036] As shown in Figure 2, the intermediate transfer apparatus 20 of the image forming apparatus 1 is integrally configured as an intermediate transfer unit 200, including the intermediate transfer belt 21, a plurality of belt support rolls 22-25, and the primary transfer apparatus 15 (Y, M, C, K). The intermediate transfer unit 200 is detachable from the apparatus body 1a.

[0037] The intermediate transfer unit 200 includes front and rear side frames 201 and 202 positioned at both ends along the width direction intersecting the direction of movement of the intermediate transfer belt 21. Belt support rolls 22-25 and the primary transfer device 15 are rotatably supported on both side frames 201 and 202. Positioning recesses 203 and 204 are provided on the front and rear side frames 201 and 202 for positioning the secondary transfer roll 31 of the secondary transfer device 30. The positioning recesses 203 and 204 are located at the ends corresponding to the belt support roll 25, which functions as a backup roll, at one end along the horizontal direction X. The intermediate transfer unit 200 is mounted and fixed at a predetermined position on the main body 1a of the image forming apparatus 1. As a result, the positioning recesses 203 and 204 are fixed together with the intermediate transfer unit 200 at the required position on the main body 1a side of the image forming apparatus 1.

[0038] As shown in Figure 1, the secondary transfer device 30 includes a secondary transfer roll 31 that rotates at the secondary transfer position T2, which is the outer circumferential surface portion of the intermediate transfer belt 21 supported by the belt support roll 25 in the intermediate transfer device 20. A DC voltage with opposite or same polarity as the charge polarity of the toner is supplied to the secondary transfer roll 31 or the belt support roll 25 of the intermediate transfer device 20 as the secondary transfer voltage.

[0039] The fixing device 40 is composed of a heating rotating body 41 and a pressurizing rotating body 42, among other components. The heating rotating body 41 is a belt-shaped or roll-shaped component that is heated by heating means such as electromagnetic induction heating or a heat source so that its surface temperature is maintained at a predetermined temperature. The pressurizing rotating body 42 is a roll-shaped or belt-shaped component that rotates in contact with the heating rotating body 41 at the required pressure. In this fixing device 40, the contact area where the heating rotating body 41 and the pressurizing rotating body 42 come into contact becomes a fixing processing unit N that performs the required fixing process (heating and pressurizing).

[0040] The paper feeder 50 is positioned below the image creation device 10 (Y, M, C, K). This paper feeder 50 mainly consists of one (or more) paper containers 52 and a paper feeder 53. The paper containers 52 store recording paper 5 of the desired size and type, stacked on a stacking plate 51. The paper feeder 53 feeds the recording paper 5 one sheet at a time from the paper containers 52. The paper containers 52 are mounted so that they can be pulled out, for example, from the front side (the side that the user faces when operating) of the device body 1a.

[0041] A paper feed transport path 57 is provided between the paper feed device 50 and the secondary transfer device 30. The paper feed transport path 57 consists of one (or more) pairs of paper transport rolls 54 and transport guide materials 55, 56 that transport the recording paper 5 fed from the paper feed device 50 to the secondary transfer position T2. ​​The pair of paper transport rolls 54 positioned immediately before the secondary transfer position T2 in the paper feed transport path 57 is configured, for example, as a roll (resist roll) that adjusts the transport timing of the recording paper 5.

[0042] Furthermore, a paper transport path 59 is provided between the secondary transfer device 30 and the fixing device 40. The paper transport path 59 consists of transport guide members 58 and the like that transport the recording paper 5 fed out from the secondary transfer device 30 to the fixing device 40.

[0043] A discharge transport path 65 is provided downstream of the fuser 40. The discharge transport path 65 includes a pair of paper transport rolls 61 and a pair of paper discharge rolls 62, as well as transport guide materials 63 and 64. The pair of paper transport rolls 61 and 62, along with the transport guide materials 63 and 64, discharge the recording paper 5, on which the toner image has been fixed by the fuser 40, to the paper discharge section 60 located at the top of the main body 1a of the device.

[0044] In this embodiment 1, as shown in Figure 3, a side cover 110 is provided as an example of an opening and closing mechanism that is attached to the main body 1a of the device so as to be openable and closable. The side cover 110 is rotatably attached to a pivot point 111 provided on the lower end of the left side surface of the main body 1a via an engaging portion 112 consisting of a recess and an insertion hole provided at its lower end. Furthermore, as shown in Figure 4, a locking member 114 is provided at the upper end of the side cover 110, which is locked to a cylindrical locking portion 113 provided on the main body 1a side by operating an operating part (not shown) when opening and closing the side cover 110, thereby locking the side cover 110 in a closed position.

[0045] The side cover 110 of the image forming apparatus 1 is opened and closed when a problem occurs with the transport of the recording paper 5 in the paper feed path 57, the paper transport path 59, or the discharge transport path 65, etc. (a so-called jam). This exposes the paper feed path 57, the paper transport path 59, or the discharge transport path 65 to the outside, allowing for the removal of the recording paper 5 that has been improperly transported. At this time, the pinch roll 54b, which is one of the transport rolls that make up the pair of paper transport rolls 54 mounted on the side cover 110, is separated from the register roll 54a, which is one of the transport rolls that make up the pair of paper transport rolls 54 mounted on the main body of the apparatus 1a. Similarly, the secondary transfer roll 31 mounted on the side cover 110 is separated from the belt support roll 25 mounted on the main body of the apparatus 1a.

[0046] In Figure 1, reference numeral 100 denotes a control device as an example of a control means that comprehensively controls the operation of the image forming apparatus 1.

[0047] <Basic operation of an image forming apparatus> The following describes the basic image forming operation of the image forming apparatus 1.

[0048] This section describes the image formation operation when forming a full-color image by combining four toner images (Y, M, C, K) using the four imaging devices 10 (Y, M, C, K). The image formation operation is basically the same when forming an image by combining single-color or multi-color toner images using one or more of the four imaging devices 10 (Y, M, C, K).

[0049] When the image forming apparatus 1 receives command information requesting an image forming operation (printing), the control device 100 controls the four image forming devices 10 (Y, M, C, K), the intermediate transfer device 20, the secondary transfer device 30, the fixing device 40, etc. to start up.

[0050] Then, in each imaging apparatus 10 (Y, M, C, K), as shown in Figure 1, first each photoreceptor drum 11 rotates in the direction indicated by arrow A, and each charging apparatus 12 charges the surface of each photoreceptor drum 11 to the required polarity and potential. Subsequently, the exposure apparatus 13 irradiates the surface of the charged photoreceptor drum 11 with light emitted based on the image signal obtained by converting the image information input to the image forming apparatus 1 into each color component (Y, M, C, K). Then, electrostatic latent images of each color component, composed of the required potential difference, are formed on the surface of each photoreceptor drum 11.

[0051] Next, each developing unit 14 (Y, M, C, K) supplies toner of the corresponding color (Y, M, C, K), charged with the required polarity, to the electrostatic latent images of each color component formed on the photoreceptor drum 11, and electrostatically deposits it to develop the image. Through this development, the electrostatic latent images of each color component formed on each photoreceptor drum 11 are revealed as four toner images (Y, M, C, K) developed with their corresponding color toners.

[0052] Next, the toner images of each color formed on the photoreceptor drum 11 of each imaging device 10 (Y, M, C, K) are transported to the primary transfer position T1. Then, the primary transfer device 15 performs a primary transfer, sequentially overlapping the toner images of each color onto the intermediate transfer belt 21 of the intermediate transfer device 20, which rotates in the direction indicated by arrow B.

[0053] Furthermore, in each imaging apparatus 10 (Y, M, C, K) where the primary transfer has been completed, the drum cleaning device 16 cleans the surface of the photoreceptor drum 11 by scraping off any adhering material. This prepares each imaging apparatus 10 (Y, M, C, K) for the next imaging operation.

[0054] Next, the intermediate transfer device 20 holds the toner image transferred in the first stage by the rotation of the intermediate transfer belt 21 and transports it to the secondary transfer position T2. ​​Meanwhile, the paper feed device 50 feeds the required recording paper 5 into the paper feed transport path 57 in accordance with the image formation operation. In the paper feed transport path 57, a pair of paper transport rolls 54 acting as registration rolls feeds and supplies the recording paper 5 to the secondary transfer position T2 in accordance with the transfer timing.

[0055] At the secondary transfer position T2, the secondary transfer roll 31 transfers the toner image on the intermediate transfer belt 21 onto the recording paper 5 in one go. After the secondary transfer is completed, the belt cleaning device 26 in the intermediate transfer device 20 cleans the surface of the intermediate transfer belt 21 by removing any toner or other deposits remaining after the secondary transfer.

[0056] Next, the recording paper 5, on which the toner image has been secondarily transferred, is peeled off from the intermediate transfer belt 21 and the secondary transfer roll 31 and then transported along the paper transport path 59 to the fuser device 40. In the fuser device 40, the recording paper 5 after the secondary transfer is introduced and passed through the fuser processing section N between the rotating heating body 41 and the pressing body 42. This performs the necessary fuser processing (heating and pressurizing) to fix the unfixed toner image to the recording paper 5. After the fuser is complete, the recording paper 5 is discharged via the discharge transport path 65 by a pair of paper discharge rolls 62 to the paper discharge section 60 located at the top of the device body 1a.

[0057] Through the above process, a full-color image is output, formed by combining toner images consisting of four toner colors (Y, M, C, K).

[0058] <Configuration of paper transport roll pairs> The image forming apparatus 1 according to this embodiment 1, as shown in Figure 1, is equipped with a pair of paper transport rolls 54 as a transport roll pair for transporting the recording paper 5 to the secondary transfer position T2 as described above. The pair of paper transport rolls 54 consists of a register roll 54a and a pinch roll 54b. The register roll 54a is rotatably mounted on a register unit 400, which is an example of a first unit, as shown in Figure 5. The register unit 400 is fixedly attached to the apparatus body 1a. The register roll 54a is rotationally driven by a drive means (not shown) provided on the apparatus body 1a. The pinch roll 54b is rotatably mounted on a pinch unit 500, which is an example of a second unit, as shown in Figure 6. The pinch unit 500 is movably attached to a side cover 110. The pinch roll 54b rotates by contacting the register roll 54a.

[0059] During paper feeding, the paper transport roll pair 54 corrects the skew of the recording paper 5 by pressing the leading edge of the recording paper 5 against the nip portions of the stopped register roll 54a and pinch roll 54b. Subsequently, the paper transport roll pair 54 transports the recording paper 5 to the secondary transfer position T2 together with the pinch roll 54b by rotating the register roll 54a. At this time, in the image forming apparatus 1, if there is a misalignment in parallelism between the register roll 54a and the secondary transfer roll 31 positioned at the secondary transfer position T2, a positional misalignment will occur in the image transferred to the recording paper 5.

[0060] Therefore, the image forming apparatus 1 is equipped with a tilt adjustment member 70 as an example of a tilt adjustment means that can adjust the tilt of the resist roll 54a to correct the misalignment of the image transferred to the recording paper 5. As shown in Figure 7, the tilt adjustment member 70 is positioned at both ends along the axial direction of the rotation axis of the resist roll 54a, that is, along the longitudinal direction of the resist unit 400. Note that Figure 7 shows the apparatus body 1a with the frame removed.

[0061] As shown in Figure 8, the tilt adjustment member 70 is formed from synthetic resin or the like, in a flat plate shape with a substantially rectangular side, with one side of its upper end (left side in the figure) protruding upward. A cylindrical or columnar shaft portion 711 (see Figure 7) is provided on the back surface of the tilt adjustment member 70 so as to protrude inward. In addition, as shown in Figure 5, support portions 401 that open to the sides are provided on both ends of the register unit 400 along its longitudinal direction. As shown in Figure 7, the shaft portion 711 of the tilt adjustment member 70 is fitted into the support portion 401 of the register unit 400 to adjust the height of the register unit 400 along the vertical direction Z. The register unit 400 is mounted on the device body 1a so as to be movable along the vertical direction Z.

[0062] As shown in Figure 8, the tilt adjustment member 70 is mounted on the front and rear frames 72 of the device body 1a so that its height along the vertical direction Z can be adjusted. The tilt adjustment member 70 has one common hole 712, several (five in the illustrated example) adjustment holes 713 to 717, and two slide holes 718 and 719. The several adjustment holes 713 to 717 adjust the height of the register unit 400 along the vertical direction Z. The common hole 712 is an elongated slot along the vertical direction Z. On the other hand, the several adjustment holes 713 to 717 are elongated slots along the horizontal direction X. The two slide holes 718 and 719 are elongated slots along the vertical direction Z. The two slide holes 718 and 719 engage with two protrusions 721 and 722 that are positioned vertically along the vertical direction Z on the frame 72 of the device body 1a. As a result, the tilt adjustment member 70 is held in a position relative to the frame 72 of the device body 1a so as to be movable along the vertical direction Z, while its position along the horizontal direction X is restricted by two slide holes 718, 719 and two protrusions 721, 722. The frame 72 of the device body 1a has regions 723 that protrude toward the front and rear sides, corresponding to the tilt adjustment member 70.

[0063] The frame 72 of the device body 1a is provided with multiple screw holes 724 to 728 corresponding to multiple adjustment holes 713 to 717 of the tilt adjustment member 70. The tilt adjustment member 70 adjusts the height of the end along the longitudinal direction of the register unit 400 by selecting one of the adjustment holes 713 to 717 from the common hole 712 and the multiple adjustment holes 713 to 717 and fastening it with screws 73 and 74 into the screw holes 724 to 728 of the device body 1a. Note that screw holes 724 and 725 are omitted from the illustration in Figure 8 because screws 73 and 74 are fastened to them.

[0064] The tilt adjustment member 70 has numerical values ​​indicating the height adjustment level, such as "-1", "-0.5", "0", "+0.5", and "+1", displayed next to each adjustment hole 713 to 717. The tilt adjustment member 70 is fixed to a reference position (height) by, for example, selecting the adjustment hole 713 marked "0" and fastening it with a screw 74 into the corresponding screw hole 724 on the frame of the device body 1a. Similarly, the tilt adjustment member 70 is fixed at a position "+0.5" higher than the reference position by, for example, selecting the adjustment hole 714 marked "+0.5" and fastening it with a screw 74 into the corresponding screw hole 725 on the frame of the device body 1a.

[0065] As described above, the tilt adjustment members 70 are positioned at both the front and rear ends of the register unit 400 along its longitudinal direction. However, the rear tilt adjustment member 70 is usually fixed to the main body 1a using a reference adjustment hole 713 marked "0". The tilt of the resist roll 54a is adjusted by adjusting the height of the register unit 400, that is, the height of the front end of the resist roll 54a along its axial direction, using only the front tilt adjustment member 70. This tilt adjustment of the resist roll 54a is basically performed when the image forming apparatus 1 is shipped. Note that the tilt of the resist roll 54a is not limited to being adjusted using only the front tilt adjustment member 70. The system may be configured to adjust the tilt of the resist roll 54a using both the front and rear tilt adjustment members 70.

[0066] Furthermore, the image forming apparatus according to this embodiment 1 is equipped with a positioning and fixing means that positions and fixes the other transport roll of the transport roll pair, which is movably mounted on the opening and closing means, to the apparatus body before the transfer means comes into contact with the image holding means when the opening and closing means is closed.

[0067] As shown in Figure 3, the pinch roll 54b, which is the other transport roll of the paper transport roll pair 54, and the secondary transfer roll 31 of the secondary transfer device 30 are mounted on the side cover 110. By rotating the side cover 110 in the direction of closing it and fixing it in a predetermined position on the main body 1a of the image forming apparatus 1, the pinch roll 54b and the secondary transfer roll 31 are positioned and fixed in an operating position that contacts the resist roll 54a and the belt support roll 25, respectively.

[0068] At this time, the pinch roll 54b mounted on the side cover 110 is configured to be positioned in an operating position where it contacts the resist roll 54a before the secondary transfer roll 31. Subsequently, the secondary transfer roll 31 mounted on the side cover 110 is positioned in an operating position where it contacts the belt support roll 25. In this way, the image forming apparatus 1 reduces the operating force required to close the side cover 110.

[0069] As shown in Figure 6, the positioning and fixing means 80 includes a guide member 81 as an example of a holding means for movably holding the pinch unit 500 to the side cover 110. The guide member 81 is positioned at both ends along the longitudinal direction of the pinch unit 500, which is the axial direction of the pinch roll 54b. The guide member 81 is made of a molded product of sheet metal or synthetic resin formed into a predetermined shape by press working, or a combination of both. The guide member 81 is fixedly attached to the inner surface of the side cover 110. Two studs 82 and 83, which constitute part of the positioning and fixing means 80, are positioned on both sides of the pinch unit 500 along the longitudinal direction. The two studs 82 and 83 are attached so as to protrude outward from both sides of the pinch unit 500 along the longitudinal direction. The two studs 82 and 83 consist of a main stud 82 and an auxiliary stud 83. The main stud 82 is formed in a cylindrical shape with a larger outer diameter than the auxiliary stud 83. The main stud 82 is located at the end of the pinch unit 500 closest to the side cover 110. The main stud 82 may be directly attached to the pinch unit 500, or it may be attached by fixing a mounting plate 821 on which the main stud 82 is embedded to the side of the pinch unit 500 with screws or the like. On the other hand, the auxiliary stud 83 is located at the upper part of the pinch unit 500, closer to the center.

[0070] The guide member 81 has first and second slit holes 811 and 812 provided at its upper end, arranged substantially parallel to each other. The first and second slit holes 811 and 812 are formed in an elongated straight shape or a slightly curved oval shape. The first and second slit holes 811 and 812 are arranged in an inclined state such that the end on the device body 1a side (right side in the figure) is located downward along the vertical direction Z. The first slit hole 811 is located closer to the side cover 110 of the guide member 81 (to the left in the figure). The second slit hole 812 is located above the first slit hole 811 along the vertical direction Z and closer to the device body 1a (to the right in the figure).

[0071] The pinch unit 500 is movable, i.e., attached to the side cover 110 in a direction toward and toward the device body 1a, via main and auxiliary studs 82, 83 and first and second slit holes 811, 812. The pinch unit 500 is also biased toward the device body 1a by a compression spring 84, which is an example of a biasing member. The compression spring 84 is interposed between the side cover 110 and the pinch unit 500 at both ends along the longitudinal direction of the pinch unit 500.

[0072] Furthermore, as shown in Figures 5 and 6, the outer surface of the guide member 81 is provided with an inclined portion 814, which is a step that protrudes outward (towards the front in the figures) in the area on the side cover 110 side. When the side cover 110 is closed, this inclined portion 814 comes into contact with the contact portion 864 of the fixed arm 86 provided on the register unit 400, causing the fixed arm 86 to rotate in a clockwise direction. The inclined portion 814 consists of a first inclined portion 814a and a second inclined portion 814b. The first inclined portion 814a comes into contact with the contact portion 864 of the fixed arm 86, causing the fixed arm 86 to rotate in a clockwise direction to a predetermined fixed position. The second inclined portion 814b holds the fixed arm 86 in the fixed position. As shown in Figure 5, the second inclined portion 814b is formed in a straight line extending radially outward from the pivot point 861 of the fixed arm 86 and the contact portion 864. Therefore, when the contact portion 864 of the fixed arm 86 moves along the second inclined portion 814b, it does not rotate further clockwise.

[0073] On the other hand, as shown in Figure 6, the main body of the device 1a has a positioning member 85 which is a fixing means that constitutes part of the positioning fixing means 80. The positioning member 85 is located at both ends along the longitudinal direction of the register unit 400 and is fixed to the end on the side cover 110 side of the upper end of the register unit 400 by means of screws or the like. The positioning member 85 is made of synthetic resin or the like and is formed in the shape of an inverted triangle with its base facing upwards. The end of the positioning member 85 on the side cover 110 side (left side in Figure 6) is provided with a positioning recess 851, which is an example of a first recess that is positioned by fitting the main stud 82 of the pinch unit 500 into it. The positioning recess 851 is formed in a substantially U-shape that opens toward the side cover 110.

[0074] Furthermore, the positioning member 85 includes a fixing arm 86 that engages with the main stud 82 of the pinch unit 500 and constitutes part of the fixing means for fixing the pinch unit 500 in the operating position. The fixing arm 86 is formed from sheet metal or synthetic resin in an elongated, substantially rectangular shape. The fixing arm 86 is attached to the positioning member 85 so as to be rotatable around a pivot point 861 provided on the positioning member 85. Near the pivot point 861 of the fixing arm 86, a stopper piece 862 protrudes downward. The stopper piece 862 of the fixing arm 86 contacts the stop pin 853 of the positioning member 85, thereby restricting its rotational position along the counterclockwise direction.

[0075] Furthermore, the tip of the fixed arm 86 is provided with a fixing recess 863, which is an example of a second recess opening in the circumferential direction intersecting the longitudinal direction of the fixed arm 86. As shown in Figure 6, the fixing recess 863 of the fixed arm 86 is set so that its opening direction intersects with that of the positioning recess 851 of the positioning member 85. As a result, the main stud 82 of the pinch unit 500 is positioned mainly along the vertical direction Z by the positioning recess 851 of the positioning member 85. The main stud 82 of the pinch unit 500 is also positioned mainly along the horizontal direction X by the fixing recess 863 of the fixed arm 86. The main stud 82 of the pinch unit 500 is biased to protrude from the positioning recess 851 by the repulsive force when the pinch roll 54b of the pinch unit 500 comes into contact with the resist roll 54a. Therefore, the main stud 82 of the pinch unit 500 is positioned and fixed in contact with the tip surface of the fixing recess 863 by this repulsive force.

[0076] Incidentally, in the image forming apparatus 1 according to this embodiment 1, as described above, the inclination of the register roll 54a among the paper transport roll pair 54 can be adjusted by the inclination adjustment member 70.

[0077] Therefore, in the image forming apparatus 1 prior to the application of Embodiment 1 of this invention, when the tilt of the resist roll 54a is adjusted by the tilt adjustment member 70, the height of the resist roll 54a changes. As a result, the position (height) of the positioning recess 851 of the positioning member 85 provided on the resist unit 400 changes along with the change in the height of the resist roll 54a. Consequently, when closing the side cover 110, the main stud 82 on the pinch unit 500 side and the positioning recess 851 of the positioning member 85 on the resist unit 500 side, which constitute the positioning fixing means 80, may interfere with each other, potentially damaging the positioning recess 851 of the positioning member 85 or causing the main stud 82 to shift away from the positioning recess 851, resulting in the pinch unit 500 not being positioned in the correct operating position and causing malfunction.

[0078] Therefore, in this embodiment 1, the image forming apparatus is configured such that the positioning and fixing means allows the movement of the other transport roll along the adjustment direction of the tilt adjustment means, and restricts the position of the other transport roll when it moves toward the end on the apparatus body side.

[0079] In other words, in the image forming apparatus 1 according to this embodiment 1, as shown in Figure 9, the opening width W of the first slit hole 811 of the guide member 81 constituting the positioning and fixing means 80 is set to be significantly wider than the outer diameter of the main stud 82. As a result, the pinch unit 500 is allowed to move along the vertical direction Z in accordance with the opening width W of the first slit hole 811 via the main stud 82. The amount of movement of the pinch unit 500 along the vertical direction Z is set to be approximately the same as the amount of movement of the register unit 400 along the vertical direction Z by the tilt adjustment member 70. However, the amount of movement of the pinch unit 500 may be set to be greater than the amount of movement of the register unit 400.

[0080] Furthermore, in the image forming apparatus 1 according to this embodiment 1, as shown in Figure 9, the pinch unit 500 is configured to restrict its position when it moves to the end on the apparatus body 1a side. As described above, the pinch unit 500 is allowed to move along the vertical direction Z by setting a wide opening width W of the first slit hole 811 of the guide member 81.

[0081] However, if the opening width W of the first slit hole 811 of the pinch unit 500 is significantly larger than the outer diameter of the main stud 82, when the pinch unit 500 moves to the end on the device body 1a side, that is, when the main stud 82 moves to the end along the longitudinal direction of the first slit hole 811, there is a risk that the position of the main stud 82 along the vertical direction Z will not be determined.

[0082] Therefore, in this embodiment 1, the pinch unit 500 is configured to allow movement along the vertical direction Z while uniformly restricting its position when it moves to the end on the device body 1a side. Specifically, the opening width w of the end 811a along the longitudinal direction of the first slit hole 811 is narrower than the opening width W of other areas and is set to be approximately equal to the outer diameter of the main stud 82. Thus, when the main stud 82 moves to the end 811a along the longitudinal direction of the first slit hole 811, the position of the main stud 82 is uniformly restricted.

[0083] As a result, when closing the side cover 110, the main stud 82 of the pinch unit 500 is movable along the vertical direction Z. Therefore, even when the height of the register unit 400 on the device body 1a side along the vertical direction Z changes due to the adjustment of the tilt adjustment member 70, the main stud 82 of the pinch unit 500 can be made to follow the change in the height of the register unit 400 along the vertical direction Z. Furthermore, the main stud 82 of the pinch unit 500 can be securely fitted into the positioning recess 851 of the positioning member 85 on the register unit 400.

[0084] The upper part of the positioning recess 851 has a curved shape with a downward protruding guide portion 852 that guides the main stud 82 into the positioning recess 851. Therefore, even if the main stud 82 of the pinch unit 500 is misaligned with respect to the positioning recess 851 of the positioning member 85 along the vertical Z direction, it is reliably guided into the positioning recess 851 via the guide portion 852.

[0085] The main stud 82 of the pinch unit 500, which is positioned by the positioning recess 851, is fixed by the fixing recess 863 of the fixing arm 86.

[0086] In this case, the inner surface of the fixing recess 863 of the fixed arm 86 is formed in an arc shape with respect to the pivot point 861. The outer surface of this fixing recess 863 defines the distance between the axes of the resist roll 54a mounted on the register unit 400 and the pinch roll 54b of the pinch unit 500 which is positioned and fixed to the register unit 400 by the positioning fixing means 80.

[0087] Therefore, the fixing recess 863 of the fixing arm 86 is formed such that its outer surface 863a is in an arc shape centered on the pivot point 861, so that even if the stopping position of the fixing arm 86 that fixes the main stud 82 of the pinch unit 500 changes, the axial distance between the resist roll 54a and the pinch roll 54b is always maintained constant.

[0088] <Configuration of the secondary transfer device> As shown in Figure 1, the secondary transfer apparatus 30 includes a secondary transfer roll 31, which is an example of a transfer means that rotates at the secondary transfer position T2, which is the outer peripheral surface portion of the intermediate transfer belt 21, an example of an image holding means supported by the belt support roll 25 in the intermediate transfer apparatus 20.

[0089] In this embodiment 1, as shown in Figure 3, the secondary transfer apparatus 30 constitutes a secondary transfer unit 300 that is detachably attached to a side cover 110, which is an example of an opening and closing mechanism for the apparatus body 1a.

[0090] The secondary transfer unit 300 is rotatably mounted with the secondary transfer roll 31 of the secondary transfer device 30. The secondary transfer unit 300 is equipped with bearing members 311 positioned at both ends of the secondary transfer roll 31 along its axial direction. When the side cover 110 of the secondary transfer unit 300 is closed, the bearing members 311 come into contact with the positioning recesses 203 and 204 of the intermediate transfer unit 200, thereby positioning and fixing the secondary transfer roll 31 to the operating position of the device body 1a.

[0091] As shown in Figure 3, the secondary transfer unit 300 is mounted on the inner surface of the side cover 110 at a position further from the pivot point 111 than the pinch unit 500. Therefore, when the side cover 110 is rotated clockwise around the pivot point 111 to close the side cover, the amount by which the secondary transfer unit 300 moves is greater than that of the pinch unit 500.

[0092] As a result, when closing the side cover 110, the pinch unit 500 contacts the register unit 400 on the device body 1a side via the positioning and fixing means before the secondary transfer unit 300, and is positioned and fixed by the positioning and fixing means. Subsequently, the secondary transfer unit 300 contacts the intermediate transfer unit 200 on the device body 1a side via the bearing member 311 and is positioned and fixed by the positioning recesses 203 and 204.

[0093] <Operation of the image forming apparatus> By the way, in the image forming apparatus according to this embodiment 1, the positioning and fixing means for positioning and fixing the other transport roll of the transport roll pair, which is attached to the opening and closing means, to the main body of the apparatus, is configured such that, compared to an apparatus where the positioning and fixing means does not correspond to the movement of the other transport roll along the adjustment direction of the tilt adjustment means, it is possible to suppress damage to the components or malfunctions caused by interference between the components constituting the positioning and fixing means when the opening and closing means is closed.

[0094] In other words, in the image forming apparatus 1 according to this embodiment 1, as shown in Figures 7 and 8, the tilt of the rotation axis of the resist roll 54a mounted on the register unit 400 is adjusted using the tilt adjustment member 70 when the product is shipped.

[0095] Then, in the image forming apparatus 1, the desired image is formed on the recording paper 5 in the presence of the user.

[0096] At this time, as shown in Figure 1, the image forming apparatus 1 receives the desired recording paper 5 from the paper feeder 50 and transports it to the secondary transfer position T2 of the intermediate transfer apparatus 20 by the paper transport roll pair 54.

[0097] Incidentally, if a problem occurs with the transport of the recording paper 5 (a so-called jam) in the paper feed path 57, paper transport path 59, or discharge transport path 65 of the image forming apparatus 1, the side cover 110 will be opened and closed.

[0098] In the image forming apparatus 1, as described above, the tilt of the rotation axis of the resist roll 54a mounted on the resist unit 400 is adjusted using the tilt adjustment member 70 when the product is shipped. Therefore, this adjustment may cause a change in the height along the vertical Z direction of the positioning member 85, which constitutes the positioning fixing means provided at the end of the resist unit 400 along the longitudinal direction.

[0099] In the image forming apparatus 1 according to this embodiment 1, when closing the side cover 110, the position of the pinch unit 500 attached to the side cover 110 along the vertical Z direction can be varied by the main stud 82 and the first slit hole 811.

[0100] Therefore, when closing the side cover 110, even if the height of the register unit 400 along the vertical Z direction fluctuates, the height of the main stud 82 of the pinch unit 500 can be adjusted in response to the change in position of the positioning member 85 provided on the register unit 400. Thus, the main stud 82 of the pinch unit 500 can be reliably positioned in the positioning recess 851 of the positioning member 85 of the register unit 400.

[0101] In this case, when the main stud 82 of the pinch unit 500 approaches the positioning member 85 of the register unit 400, the main stud 82 moves to the end 811a along the longitudinal direction of the first slit hole 811, thereby restricting its position. Therefore, even if the position of the main stud 82 of the pinch unit 500 is allowed to fluctuate, the main stud 82 is positioned relative to the positioning recess 851 of the positioning member 85 of the register unit 400, thus avoiding interference with other members.

[0102] The main stud 82 of the pinch unit 500 is positioned in the positioning recess 851 of the register unit 400, and then the side cover 110 is rotated clockwise to engage with the fixing recess 863 of the fixing arm 86 and secure it in place.

[0103] At this time, variations may occur in the rotation angle until the fixed arm 86 stops at the stopping position, depending on the positional accuracy of the inclined portion 814 of the pinch unit 500.

[0104] However, in the image forming apparatus 1 according to this embodiment 1, the outer surface of the fixing recess 863 of the fixed arm 86 is formed in an arc shape centered on the pivot point 861. Therefore, even if there is variation in the stopping position of the fixed arm 86, the main stud 82 of the pinch unit 500 is fixed in a constant position by the arc-shaped outer surface of the fixing recess 863 of the fixed arm 86. As a result, the distance between the axes of the resist roll 54a of the resist unit 400 and the pinch roll 54b of the pinch unit 500 can always be kept constant.

[0105] <Embodiment 2> Figure 10 is a configuration diagram showing the main parts of an image forming apparatus according to Embodiment 2 of this invention.

[0106] In the image forming apparatus according to Embodiment 2 of this invention, as shown in Figure 10, instead of setting a narrower opening width at the end position of the first slit hole 811 provided in the guide member 81, a compression spring with a larger spring constant than that of Embodiment 1 is used as the compression spring 84 that biases the pinch unit 500.

[0107] The first slit hole 811 of the guide member 81 is formed in an elongated oval shape, and its end along its longitudinal direction is formed in an arc shape. Therefore, by using a compression spring 84 with a large spring constant as the compression spring 84 that biases the pinch unit 500, when the pinch unit 500 moves toward the device body 1a, the pressing force of the compression spring 84 makes it possible to hold the position of the main stud 82 of the pinch unit 500 at the end 811a along the longitudinal direction of the first slit hole 811.

[0108] Therefore, as in Embodiment 1, it is not necessary to provide a portion with a narrowed opening width at the end of the first slit hole 811 along the longitudinal direction.

[0109] The other configurations and operations are the same as in Embodiment 1, so their description will be omitted.

[0110] In the above embodiment, a color image forming apparatus equipped with four imaging devices 10Y, 10M, 10C, and 10K for yellow (Y), magenta (M), cyan (C), and black (K) was described. However, the invention is not limited to this, and the same can be applied to a monochrome image forming apparatus equipped with only a black (K) imaging device.

[0111] Furthermore, although the above embodiment described the case where the opening and closing means is applied to the side cover, it is not limited to this, and of course, the opening and closing means can be any cover to which the transfer means is attached, such as the front cover or the back cover.

[0112] (Note) (((1))) An opening / closing mechanism is attached to the main body of the device so as to be openable and closable, The opening and closing means is provided with a transfer means that transfers an image from the image holding means to the recording medium at the transfer position, A pair of transport rolls for transporting the recording medium to the transfer position, An inclination adjustment means for adjusting the inclination of one of the conveying rolls of the conveying roll pair that is mounted on the main body of the device, A means for positioning and fixing the other conveyor roll of the conveyor roll pair, which is movably mounted on the opening / closing means, to the device body before the transfer means comes into contact with the image holding means when the opening / closing means is closed, the positioning and fixing means allows the other conveyor roll to move along the adjustment direction of the tilt adjustment means and restricts the position of the other conveyor roll when it moves to the end on the device body side, An image forming apparatus equipped with the following features. (((2))) The positioning and fixing means is provided on the opening and closing means and holds the other transport roll so that it can move between a temporary holding position and a transport position while allowing it to move along the adjustment direction of the tilt adjustment means, The device body is provided with fixing means for positioning and fixing the other conveying roll to the conveying position, The image forming apparatus according to (((1))) comprising: (((3))) The image forming apparatus according to (((2))), wherein the holding means movably holds the other conveyor roll by a movable mechanism comprising a regulating member for regulating the position of the other conveyor roll, an elongated hole into which the regulating member is fitted, and a biasing member for biasing the regulating member toward the main body of the apparatus. (((4))) The image forming apparatus according to (((3))), wherein the holding means holds the other conveyor roll so that it can move along the adjustment direction of the tilt adjustment means by setting the opening width of the elongated hole in a direction intersecting the movement direction of the other conveyor roll to be wider than the regulating member. (((5))) The image forming apparatus according to (((3))), wherein the holding means restricts the position of the regulating member when it moves to the end of the elongated hole on the device body side, thereby restricting the position of the other conveying roll when it moves to the end on the device body side. (((6))) The image forming apparatus according to (((3))), wherein the fixing means comprises a positioning member provided on the main body of the apparatus and having a first recess into which the restricting member is fitted, and a fixing member having a second recess that engages with the restricting member to fix the restricting member in the first recess. (((7))) The image forming apparatus according to (((6))), wherein the second recess of the fixing member is opened in a direction intersecting the opening direction of the first recess. (((8))) The image forming apparatus according to (((6))), wherein the fixing member comprises a fixing arm member that is rotatably provided on a holder that holds one of the transport rolls with respect to a center of rotation. (((9))) The image forming apparatus according to ((8)), wherein the second recess of the fixed arm member has an engagement surface with the regulating member that is formed in an arc shape centered on the rotation center.

[0113] In the image forming apparatus according to (((1))), compared to an apparatus in which the positioning and fixing means for positioning and fixing the other transport roll of the transport roll pair, which is attached to the opening and closing means, to the main body of the apparatus, does not correspond to the movement of the other transport roll along the adjustment direction of the tilt adjustment means, it is possible to suppress damage to the components or malfunctions caused by interference between the components constituting the positioning and fixing means when the opening and closing means is closed. In the image forming apparatus according to (((2))), the positioning and fixing means can suppress interference between the members constituting the positioning and fixing means, which can lead to damage to the members or malfunctions, compared to a case where the other transport roll is not allowed to move along the adjustment direction of the tilt adjustment means. In the image forming apparatus according to (((3))), the holding means can simplify the configuration of the movable mechanism compared to the case in which the other transport roll is movably held by a link mechanism or the like. According to the image forming apparatus described in (((4))), the holding means can suppress damage to the member and malfunctions with a simpler configuration compared to the case where the opening width of the elongated hole is equal to that of the regulating member. According to the image forming apparatus described in (((5))), the holding means can reliably position the regulating member toward the apparatus body compared to a case where the position of the regulating member moved to the end of the elongated hole toward the apparatus body is not regulated. In the image forming apparatus according to (((6))), the fixing means can reliably position and fix the regulating member compared to the case in which only a positioning member provided on the apparatus body side and having a first recess into which the regulating member is fitted is provided. According to the image forming apparatus of (((7))), the second recess of the fixing member can securely fix the regulating member by the second recess, compared to the case where the first recess is open in the same direction as the opening direction. In the image forming apparatus according to (((8))), the fixing member can be easily made to intersect the opening directions of the second recess and the first recess, compared to the case in which the fixing member is not composed of a fixing arm member that is rotatably provided on a holder that holds one of the transport rolls with respect to a rotation center. According to the image forming apparatus described in (((9))), the second recess of the fixed arm member can maintain a constant contact force with the other conveying roll even when the position of one conveying roll changes, compared to the case where the engagement surface with the regulating member is formed in a straight line. [Explanation of symbols]

[0114] 1…Image forming apparatus 1a...Main unit of the device 30…Secondary transfer device 31... Secondary transfer roll 54... Paper transport roll pair 54a... Resist Roll 54b... Pinch roll 70... Inclination adjustment member 80...Positioning and fixing means 81... Guide member 82... Main Stud 83... Auxiliary studs 811...First slit hole 812...Second slit hole 85…Positioning member 851…Positioning recess 86... Fixed arm 863... Recess for fixing 400... Register unit 500... Pinch Unit

Claims

1. An opening / closing mechanism is attached to the main body of the device so as to be openable and closable, The opening and closing means is provided with a transfer means that transfers an image from the image holding means to the recording medium at the transfer position, A pair of transport rolls for transporting the recording medium to the transfer position, An inclination adjustment means for adjusting the inclination of one of the conveying rolls of the conveying roll pair that is mounted on the main body of the device, A means for positioning and fixing the other conveyor roll of the conveyor roll pair, which is movably mounted on the opening / closing means, to the device body before the transfer means comes into contact with the image holding means when the opening / closing means is closed, the positioning and fixing means allows the other conveyor roll to move along the adjustment direction of the tilt adjustment means and restricts the position of the other conveyor roll when it moves to the end on the device body side, An image forming apparatus equipped with the following features.

2. The positioning and fixing means is provided on the opening and closing means and holds the other transport roll so that it can move between a temporary holding position and a transport position while allowing it to move along the adjustment direction of the tilt adjustment means, The device body is provided with fixing means for positioning and fixing the other conveying roll to the conveying position, The image forming apparatus according to claim 1, comprising:

3. The image forming apparatus according to claim 2, wherein the holding means movably holds the other conveyor roll by a movable mechanism comprising a regulating member for regulating the position of the other conveyor roll, an elongated hole into which the regulating member is fitted, and a biasing member for biasing the regulating member toward the main body of the apparatus.

4. The image forming apparatus according to claim 3, wherein the holding means holds the other conveyor roll so that it can move along the adjustment direction of the tilt adjustment means by setting the opening width of the elongated hole in a direction intersecting the movement direction of the other conveyor roll to be wider than that of the regulating member.

5. The image forming apparatus according to claim 3, wherein the holding means restricts the position of the regulating member when it moves to the end of the elongated hole on the device body side, thereby restricting the position of the other conveying roll when it moves to the end on the device body side.

6. The image forming apparatus according to claim 3, wherein the fixing means comprises a positioning member provided on the main body side of the apparatus and having a first recess into which the restricting member is fitted, and a fixing member having a second recess that engages with the restricting member to fix the restricting member in the first recess.

7. The image forming apparatus according to claim 6, wherein the second recess of the fixing member is opened in a direction intersecting the opening direction of the first recess.

8. The image forming apparatus according to claim 6, wherein the fixing member comprises a fixing arm member that is rotatably provided on a holder that holds one of the transport rolls, with respect to a rotation center.

9. The image forming apparatus according to claim 8, wherein the second recess of the fixed arm member has an engagement surface with the regulating member formed in an arc shape centered on the rotation center.

Images