JP2014097864A - Media transportation member and image formation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent force in a direction which stops backlash from becoming excessive.SOLUTION: The media transportation member Ra comprises: a support member 13 which supports a body 1 of one transportation member movably toward a direction coming close to and separating toward a body 2 of the other transportation member; a first press member 14 which actuates pressing force by which the body 1 of one transportation member is pressed toward the body 2 of the other transportation member; and a second press member 16 which actuates pressing force by which the body 1 of one transportation member is pressed along a transportation direction of the media.

Description

  The present invention relates to a medium conveying member and an image forming apparatus.

  In a conventional image forming apparatus, a technique described in Patent Document 1 below is conventionally known as a technique related to a conveying member that conveys a medium.

  Japanese Patent Application Laid-Open No. 2002-344163 as Patent Document 1 describes a configuration in which a bearing (13) of a rubber roller (17) supported by an opening / closing cover (21) is pressed by a compression spring (15). In the configuration described in Patent Document 1, when the opening / closing cover (21) is closed, the pressure on the main body side of the rubber roller (8) and the rubber roller (17) is set by the pressing force of the compression spring (15). Contact in the state that acted.

JP 2002-344163 A (“0028” to “0030”, FIG. 5)

  This invention makes it a technical subject to suppress that the force of the direction which suppresses rattling is excessive.

In order to solve the technical problem, a medium transporting member according to claim 1 is provided.
A pair of conveying members disposed between the medium and conveying the medium;
A support member that supports the main body of the one transport member so as to be movable toward and away from the main body of the other transport member;
A first pressing member that applies a force to push the main body of the one transport member against the main body of the other transport member;
A second pressing member that applies a force to push the main body of the one transport member along the transport direction of the medium;
It is provided with.

In order to solve the technical problem, a medium transporting member according to claim 2 is provided.
A pair of conveying members disposed between the medium and conveying the medium;
A support member that supports the main body of the one transport member so as to be movable toward and away from the main body of the other transport member;
A pressing portion extending in a direction in which the main body of the one transport member is pressed against the main body of the other transport member and in a direction inclined with respect to the transport direction of the medium, and the main body of the one transport member is A pressing member that exerts a force having a component in a direction to be pressed against the main body of the transport member and a component along the transport direction of the medium, and is against the rotation center of the main body of the other transport member When the rotation center of the main body of the one transport member moves away from the main body, the pressing portion elastically deforms in a direction approaching the state along the transport direction of the medium, and the one of the transport members is elastically restored by the elastic restoring force. The pressing member that increases the force of the component in the direction in which the main body of the transport member is directed toward the main body of the other transport member;
It is provided with.

In order to solve the technical problem, an image forming apparatus according to claim 3 is provided.
The medium conveying member according to claim 1 or 2,
A recording unit for recording an image on a medium conveyed by the medium conveying member;
It is provided with.

According to a fourth aspect of the present invention, in the image forming apparatus according to the third aspect,
A transport path through which the medium is transported;
An opening / closing member movable between an open position for opening the conveyance path to the outside and a closing position for closing the conveyance path;
A main body of the one conveying member supported by the opening and closing member;
A main body of the other transport member supported by the main body of the image forming apparatus;
It is provided with.

According to the first to third aspects of the present invention, it is possible to suppress an excessive force in the direction of suppressing rattling as compared with the case where the configuration of the present invention is not provided.
According to invention of Claim 4, compared with the case where it does not have the structure of this invention, it can suppress that force required when opening and closing an opening / closing member becomes excess.

FIG. 1 is an explanatory diagram of an image forming apparatus according to a first embodiment of the present invention. FIG. 2 is a perspective view of the opening / closing member on which the conveyance member of Example 1 is supported. FIG. 3 is an explanatory diagram of a main part of the conveying member according to the first embodiment. FIG. 4 is an explanatory diagram of a conventional conveying member pressing structure. FIG. 5 is an explanatory diagram of the conveying member according to the second embodiment and corresponds to FIG. 3 according to the first embodiment. FIG. 6 is an explanatory diagram of the conveying member of Example 3, FIG. 6A is a diagram corresponding to FIG. 3 of Example 1, and FIG. 6B is a change from the state shown in FIG. It is explanatory drawing in the case.

Next, examples as specific examples of embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following examples.
In order to facilitate understanding of the following description, in the drawings, the front-rear direction is the X-axis direction, the left-right direction is the Y-axis direction, the up-down direction is the Z-axis direction, and arrows X, -X, Y, -Y, The direction indicated by Z and -Z or the indicated side is defined as the front side, the rear side, the right side, the left side, the upper side, the lower side, or the front side, the rear side, the right side, the left side, the upper side, and the lower side, respectively.
In the figure, “•” in “○” means an arrow heading from the back of the page to the front, and “×” in “○” is the front of the page. It means an arrow pointing from the back to the back.
In the following description using the drawings, illustrations other than members necessary for the description are omitted as appropriate for easy understanding.

FIG. 1 is an explanatory diagram of an image forming apparatus according to a first embodiment of the present invention.
In FIG. 1, a copier U as an example of an image forming apparatus according to the first exemplary embodiment is an example of a recording unit, and includes a printer unit U1 as an example of an image recording apparatus. A scanner unit U2 as an example of a reading unit and an example of an image reading device is supported on the upper portion of the printer unit U1. An auto feeder U3 as an example of a document transport device is supported on the upper portion of the scanner unit U2. The scanner unit U2 of the first embodiment supports a user interface U0 as an example of an input unit. The user interface U0 can be operated by the operator by inputting the user interface U0.

  A document tray TG1 as an example of a medium container is disposed on the upper part of the auto feeder U3. A plurality of documents Gi to be copied can be stacked and stored in the document tray TG1. A document discharge tray TG2 as an example of a document discharge unit is formed below the document tray TG1. A document transport roll U3b is disposed along the document transport path U3a between the document tray TG1 and the document discharge tray TG.

A platen glass PG as an example of a transparent document table is disposed on the upper surface of the scanner unit U2. In the scanner unit U2 of the first embodiment, a reading optical system A is disposed below the platen glass PG. The optical system A for reading in Example 1 is supported so as to be movable in the left-right direction along the lower surface of the platen glass PG. The reading optical system A is normally stopped at the initial position shown in FIG.
On the left side of the optical system A for reading, an imaging element CCD as an example of an imaging member is disposed. An image processing unit GS is electrically connected to the image sensor CCD.
The image processing unit GS is electrically connected to the writing circuit DL of the printer unit U1. The writing circuit DL is electrically connected to an exposure apparatus ROS as an example of a latent image forming apparatus.

A photosensitive drum PR, which is an example of an image carrier, is disposed below the exposure apparatus ROS. The photosensitive drum PR rotates in the direction of the arrow Ya.
On the photosensitive drum PR, a charging roll CR, which is an example of a charger, is disposed opposite to the charging area Q0. A charging voltage is applied from the power supply circuit E to the charging roll CR. The power supply circuit E is controlled by a controller C as an example of a control unit. The controller C performs various controls by transmitting and receiving signals to and from the image processing unit GS and the writing circuit DL.
In the writing area Q1 set on the downstream side of the charging area Q0 with respect to the rotation direction of the photosensitive drum PR, a laser beam L as an example of writing light from the exposure device ROS is formed on the surface of the photosensitive drum PR. Is irradiated.
In the developing area Q2 set on the downstream side of the writing area Q1 with respect to the rotation direction of the photosensitive drum PR, the developing device G is disposed to face the surface of the photosensitive drum PR.

On the left side of the developing device G, a cartridge K as an example of a developer container is disposed. The cartridge K is detachably attached to a cartridge holder KS as an example of a container support member. Below the cartridge holder KS, a reserve tank RT as an example of a temporary storage portion for the developer is disposed. The reserve tank RT and the developing device G are connected by a developer transport device GH.
A transfer area Q3 is set on the downstream side of the development area Q2 with respect to the rotation direction of the photosensitive drum PR.

Under the printer unit U1, paper feed trays TR1 to TR4 as examples of a medium container are detachably supported. Sheets T as an example of a medium are accommodated in the sheet feed trays TR1 to TR4.
A pickup roll Rp as an example of a medium take-out member is disposed on the upper left side of the paper feed trays TR1 to TR4. On the left side of the pick-up roll Rp, a separating roll Rs as an example of a separating member is disposed.
On the left side of each of the paper feed trays TR1 to TR4, a medium transport path SH1 extending upward is formed. A plurality of transport rolls Ra as an example of a medium transport member are arranged in the transport path SH1.

An opening / closing cover U4 as an example of an opening / closing member is supported on the left side surface of the lower portion of the printer unit U1. The open / close cover U4 is supported so as to be movable between an open position indicated by a broken line in FIG. 1 and a closed position indicated by a solid line. When the opening / closing cover U4 moves to the open position, the transport path SH1 is opened to the outside. Therefore, when the opening / closing cover U4 is moved to the release position, the sheet S jammed in the conveyance path SH1 can be removed.
A registration roll Rr as an example of a feeding member is disposed downstream of the conveyance roll Ra and upstream of the transfer region Q3 with respect to the conveyance direction of the sheet S.

  On the left side of the cartridge holder KS or the like, a manual feed tray TRt, which is an example of a medium storage container and serves as a manual feed portion, is installed. The manual feed tray TRt according to the first exemplary embodiment is supported to be rotatable about the rotation center TRt0. Therefore, the manual feed tray TRt is configured to be movable between a housed position shown by a solid line in FIG. 1 and a feedable position shown by a one-dot chain line in FIG. When the manual feed tray TRt according to the first embodiment is moved to the stored position, a part TRt1 of the manual feed tray TRt is accommodated in a state of entering the lower side of the cartridge holder KS and the left side of the reserve tank RT. . Accordingly, the entire copying machine U is reduced in capacity and reduced in size.

In the transfer area Q3, a transfer unit TU, which is an example of a transfer device and an example of a medium transport device, is disposed below the photosensitive drum PR. The transfer unit TU includes an endless transfer belt TB as an example of a medium transport member.
The transfer belt TB is rotatably supported by a driving roll Rd as an example of a driving member and a driven roll Rf as an example of a driven member.
Inside the transfer belt TB, a transfer roll TR as an example of a transfer device is supported. The transfer roll TR is disposed to face the photosensitive drum PR with the transfer belt TB interposed therebetween. Therefore, the transfer region Q3 is constituted by the region where the transfer roll TR and the photosensitive drum PR face each other. A transfer voltage is applied from the power supply circuit E to the transfer roll TR.

A peeling claw SC as an example of a medium peeling member is disposed at the right end of the transfer belt TB. Below the peeling claw SC, a belt cleaner CLb as an example of a cleaner of the transfer device is disposed to face the surface of the transfer belt TB.
Note that a drum cleaner CLp, which is an example of an image carrier cleaner, is disposed on the downstream side of the transfer region Q3 with respect to the rotation direction of the photosensitive drum PR so as to face the surface of the photosensitive drum PR. Yes.

A fixing device F is disposed on the right side of the transfer unit TU. The fixing device F includes a heating roll Fh as an example of a heating rotating member and a pressure roll Fp as an example of a pressing rotating member.
To the right of the fixing device F, a discharge path SH2 extending upward is connected as an example of a medium transport path.
In the discharge path SH2, as an example of a medium transport member, a transport roll Rb and a discharge roll Rh capable of transporting the medium and rotating in the forward and reverse directions are arranged.
On the upper surface of the printer unit U1, a paper discharge tray Rh as an example of a medium discharge unit is formed.

A reversing path SH3, which is an example of a medium transport path, is formed below the discharge path SH2. The reversing path SH3 according to the first embodiment branches from the discharge path SH2 and extends downward, and joins the transport path SH1 on the upstream side in the sheet transport direction from the registration roll Rr.
A gate MG as an example of a transfer direction switching member is disposed at a branch portion between the discharge path SH2 and the reversal path SH3. The gate MG of the first embodiment is formed of an elastically deformable thin film shape, so-called film. When the sheet S conveyed from the fixing device F passes through the gate MG, the gate MG is pushed by the sheet S and is elastically deformed so that the sheet S can pass through the discharge path SH2. When the sheet S is conveyed from the discharge path SH2 to the reversing path SH3, the gate MG is held in an elastically restored state, preventing the sheet S from entering the fixing device F, and the reversing path SH3. It arrange | positions so that the sheet | seat S may be guided to the side.

(Description of image forming operation)
The plurality of documents Gi stored in the document tray TG1 sequentially passes through the document reading position on the platen glass PG and is discharged to the document discharge tray TG2.
When the automatic feeder U3 is used to automatically convey and copy a document, each document that sequentially passes through the reading position on the platen glass PG with the reading optical system A stopped at the initial position. Gi is exposed.
When the operator places the document Gi on the platen glass PG by hand, the optical system A for reading moves in the left-right direction, and the document on the platen glass PG is scanned while being exposed.
The reflected light from the document Gi passes through the optical system A and is collected on the image sensor CCD. The image pickup device CCD converts the reflected light of the original collected on the image pickup surface into an electric signal.

The image processing unit GS converts the read signal input from the image sensor CCD into a digital image signal and outputs the digital image signal to the writing circuit DL of the printer unit U1. The writing circuit DL outputs a control signal corresponding to the input image writing signal to the exposure apparatus ROS.
The surface of the photosensitive drum PR is charged by the charging roll CR in the charging region Q0. At the latent image writing position Q1, the laser beam L output from the exposure apparatus ROS forms an electrostatic latent image on the surface of the photoconductor PR. In the developing region Q2, the developing device G develops the electrostatic latent image on the photosensitive drum PR that passes through the developing region Q2 into a toner image Tn as an example of a visible image. When the developer is consumed in the developing device G, the developer transport device GH is operated according to the consumption amount, and the developer is supplied from the cartridge K to the developing device G.

The sheets S of the respective trays TR1 to TR4 are taken out by the pickup roll Rp at a preset sheet feeding time. The sheets S picked up by the pickup roll Rp are separated one by one by the separating roll Rs when picked up in a state where a plurality of sheets S are overlapped. The sheet S that has passed the separating roll Rs is conveyed to the registration roll Rr by a plurality of conveyance rolls Ra.
The sheet S fed from the manual feed tray TRt also joins the transport path SH and is transported to the registration roll Rr.

The sheet S conveyed to the registration roll Rr is transferred from the sheet guide SG1 before transfer as an example of a guide member before transfer to the transfer area according to the timing when the toner image on the surface of the photosensitive drum PR moves to the transfer area Q3. It is transported toward Q3.
The sheet S conveyed from the registration roll Rr is supported on the surface of the transfer belt TB and passes through the transfer region Q3. The toner image Tn on the surface of the photosensitive drum PR is transferred to the sheet S passing through the transfer region Q3 by the transfer voltage applied to the transfer roll TR.
The surface of the photosensitive drum PR after passing through the transfer region Q3 is cleaned by removing residual toner by the drum cleaner CLp. The surface of the photosensitive drum PR after cleaning is recharged by the charging roll CR.

The sheet S to which the toner image Tn is transferred is peeled from the transfer belt TB by the peeling claw SC. From the transfer belt TB from which the sheet S has been peeled off, deposits such as developer and paper dust attached to the surface of the transfer belt TB are removed by the belt cleaner CLb. When the sheet S peeled from the transfer belt TB passes through the contact area between the heating roll Fh and the pressure roll Fp, the toner image is heated and pressed to be fixed.
The recording sheet S on which the toner image is fixed passes through the gate MG while being elastically deformed, and is conveyed to the discharge path SH2. The sheet S discharged to the paper discharge tray TRh is transported by the transport roll Rb and discharged to the paper discharge tray TRh by the discharge roll Rh.

  When duplex printing is performed, the trailing edge of the sheet S on which one side has been recorded is conveyed downstream by the conveyance roll Rb and the discharge roll Rh until it passes through the gate MG. When the trailing edge of the sheet S passes through the gate MG, the transport roll Rb and the discharge roll Rh rotate in the reverse direction and are transported from the discharge path SH2 toward the reversal path SH3. That is, the sheet S is so-called switched back with the conveyance direction reversed. The switched sheet S is guided by the gate MG and conveyed through the reversing path SH3. The sheet S conveyed on the reversing path SH3 joins the conveying path SH1, and is conveyed to the registration roll Rr with the front and back sides reversed. Then, an image is printed on the second surface of the sheet S in the transfer region Q3.

(Description of Conveying Member of Example 1)
FIG. 2 is a perspective view of the opening / closing member on which the conveyance member of Example 1 is supported.
1 and 2, the opening / closing cover U4 according to the first embodiment is rotatably supported by the printer unit U1 around the rotation center U4a at the lower end. A hook U4b as an example of a hooking portion is rotatably supported on the upper end portion of the opening / closing cover U4. The hook U4b is connected to a handle U4c as an example of an operation unit. The hook U4b is caught in an opening (not shown) provided in the printer unit U1, and holds the opening / closing cover U4 in the closed position. Further, the hook U4b rotates when the user grips the handle U4c and comes off the opening. Accordingly, the lock between the opening / closing cover U4 and the printer unit U1 is released, and the opening / closing cover U4 is movable to the open position.

FIG. 3 is an explanatory diagram of a main part of the conveying member according to the first embodiment.
1 and 2, the conveyance roller Ra according to the first embodiment includes a driven roll 1 supported by an opening / closing cover U4 as an example of a main body of one conveyance member, and a printer unit as an example of a main body of the other conveyance member. And a drive roll 2 supported by U1. Drive is transmitted to the drive roll 2 from a motor as an example of a drive source (not shown) provided in the printer unit U1.
In FIG. 3, the driven roll 1 has a rotating shaft 1a extending in the front-rear direction. Both ends of the rotating shaft 1a are supported by bearings 12 as an example of bearing members. The rotating shaft 1a of the driven roll 1 as an example of the guided portion passes through the bearing 12 and protrudes outward in the front-rear direction.

The bearing 12 is supported by a box-shaped guide 13 formed on the opening / closing cover U4 as an example of a support member. The guide 13 is formed with a guide groove 13a as an example of a guide portion. The guide groove 13 a according to the first embodiment extends along an extension line 13 b of a line segment connecting the rotation center 1 a of the driven roll 1 and the rotation center 2 a of the drive roll 2. The rotating shaft 1a is accommodated in the guide groove 13a. Therefore, the driven roll 1 is supported so as to be movable in the direction approaching and separating from the drive roll 2 along the guide groove 13a.
In the guide 13 of the first embodiment, a support plate 13c as an example of a support portion of the second pressing member is formed at a position corresponding to the lower side of the right end of the guide groove 13a.

A first coil spring 14 as an example of a first pressing member is disposed between the left end of the bearing 12 and the guide 13. The first coil spring 14 applies a force that pushes the driven roll 1 toward the drive roll 2 via the bearing 12.
Further, a second coil spring 16 as an example of a second pressing member is disposed between the lower surface of the bearing 12 and the spring support plate 13c. The second coil spring 16 applies a force that pushes the bearing 12 upward, which is a direction along the conveyance direction of the medium.

(Description of the function of the conveyance member of Example 1)
In the conveyance roller Ra according to the first embodiment having the above-described configuration, the contact pressure between the driven roll 1 and the drive roll 2 is ensured by the pressing force of the first coil spring 14. Here, the driven roll 1 is movable along the guide groove 13a, and there is rattling between the guide groove 13a and the rotating shaft 1a. Therefore, in the conventional configuration in which the second coil spring 16 is not provided, every time the sheet S passes, abnormal noise may occur due to contact between the guide groove 13a and the rotating shaft 1a. On the other hand, in the first embodiment, the second coil spring 16 pushes the bearing 12 upward. Therefore, the rotating shaft 1a is pressed against the guide groove 13a. Therefore, rattling when the rotary shaft 1a moves along the guide groove 13a is suppressed, and generation of abnormal noise is reduced.

FIG. 4 is an explanatory diagram of a conventional conveying member pressing structure.
In FIG. 4, in the conventional conveying member, a configuration in which the direction in which the coil spring 04 pushes is inclined with respect to a line segment 03 connecting the rotation center 01a of the driven roll 01 and the rotation center 02a of the drive roll 02. Exists. In this configuration, one coil spring 04 applies a contact pressure between the driven roll 01 and the drive roll 02 and suppresses rattling.
However, in the conventional configuration shown in FIG. 4, if the pressing force of the coil spring 04 is increased in an attempt to increase the contact pressure between the driven roll 01 and the drive roll 02 in accordance with a change in design or specifications such as corresponding to thick paper. The component force along the conveying direction of the sheet S is also increased. When the component force along the transport direction increases, the frictional resistance between the shaft 06 of the driven roll 01 and the guide groove 07 increases. Therefore, when the open / close cover 08 is closed, the frictional resistance when the driven roll 01 is moved in contact with the drive roll 02 and moves along the guide groove 07 is increased. Therefore, there is a problem that the force required when the user closes the opening / closing cover 08 becomes large. Further, when the necessary force increases, there is a problem that the hook of the opening / closing cover 08 is not completely applied.

  On the other hand, in the conveyance roller Ra of the first embodiment, the first coil spring 14 and the second coil spring 16 are separated from each other, and the first coil spring 14 is compared with the prior art shown in FIG. Even if the pressing force of is increased, the increase in the frictional resistance between the rotating shaft 1a and the guide groove 13a can be reduced. Therefore, in the conveyance roller Ra of the first embodiment, even if the contact pressure between the driven roll 1 and the drive roll 2 is increased, the force in the direction of suppressing the rattling is excessive as compared with the prior art shown in FIG. Can be suppressed.

FIG. 5 is an explanatory diagram of the conveying member according to the second embodiment and corresponds to FIG. 3 according to the first embodiment.
In the description of the second embodiment, components corresponding to those of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
The second embodiment is different from the first embodiment in the following points, but is configured in the same manner as the first embodiment in other points.
In FIG. 5, in the transport roll Ra of the second embodiment, a plate spring 21 as an example of a second pressing member is disposed instead of the second coil spring 16 of the first embodiment. As for the leaf | plate spring 21 of Example 2, the base end part is integrally formed in the bearing 12, and the front-end | tip part is contacting the support plate 13c.

(Function of Example 2)
Also in the transport roll Ra of the second embodiment having the above configuration, the first coil spring 14 and the leaf spring 21 push the driven roll 1 in different directions as in the first embodiment. Therefore, as in the first embodiment, the force in the direction of suppressing rattling can be adjusted independently of the contact pressure between the driven roll 1 and the drive roll 2.

FIG. 6 is an explanatory diagram of the conveying member of Example 3, FIG. 6A is a diagram corresponding to FIG. 3 of Example 1, and FIG. 6B is a change from the state shown in FIG. 6A to a larger outer diameter of the driven roll 1. It is explanatory drawing in the case.
In the description of the third embodiment, components corresponding to those of the first and second embodiments are denoted by the same reference numerals, and detailed description thereof is omitted.
The third embodiment is different from the first and second embodiments in the following points, but is configured in the same manner as the first and second embodiments in other points.
In FIG. 6A, in the transport roll Ra of the third embodiment, the bearing 12 of the first embodiment is omitted, and instead of the first coil spring 14 and the second coil spring 16 of the first embodiment, an example of a pressing member. A leaf spring 26 is arranged. The leaf spring 26 according to the third embodiment includes a base end portion 26a that is disposed at the left end and extends in the vertical direction. The base end portion 26 a is fixedly supported by the guide 13. As an example of a direction inclined with respect to the conveyance direction of the sheet S, a pressing portion 26b extending obliquely downward to the right is formed at the upper end of the base end portion 26a. As an example of the bearing portion, the pressing portion 26b is formed with a recess 26c that receives the rotation shaft 1a at a position corresponding to the rotation shaft 1a.

(Function of Example 3)
In the conveyance roll Ra of Example 3 having the above-described configuration, the pressing portion 26b is inclined with respect to the conveyance direction of the sheet S and the extension line 13b. Therefore, the leaf spring 26 exerts a component force that presses the driven roll 1 against the drive roll 2 and a component force that presses the rotary shaft 1a against the guide groove 13a.
In the transport roll Ra according to the third embodiment, when adjusting the contact pressure between the driven roll 1 and the driving roll 2, for example, as shown in FIG. One rotating shaft 1 a can be considered to be separated from the rotation center 2 a of the drive roll 2. In this case, the leaf spring 26 is elastically deformed in the compressing direction, and the pressing portion 26b is elastically deformed in a direction approaching the state along the conveying direction of the sheet S. Accordingly, the inclination angle of the pressing portion 26b with respect to the base end portion 26a is reduced, and the component force for pressing the driven roll 1 against the drive roll 2 is increased, but the component force in the direction for pressing the rotating shaft 1a against the guide groove 13a is increased. Is suppressed.

Therefore, in the transport roll Ra of the third embodiment, as in the first embodiment, even if the contact pressure between the driven roll 1 and the drive roll 2 is increased, the contact pressure between the rotating shaft 1a and the guide groove 13a becomes excessive. It is suppressed.
In the transport roll Ra of the third embodiment, for example, the leaf spring 26 is thickened to increase the rigidity, the pressing force is increased, and the inclination angle of the pressing portion 26b with respect to the base end portion 26a is adjusted. It is also possible to adjust the component force in the direction in which the rotating shaft 1a is pressed against the guide groove 13a. Therefore, it is possible to prevent the contact pressure between the rotating shaft 1a and the guide groove 13a from becoming excessive while increasing the contact pressure between the driven roll 1 and the drive roll 2 by changing the configuration and shape of the leaf spring 26. is there.

(Example of change)
As mentioned above, although the Example of this invention was explained in full detail, this invention is not limited to the said Example, A various change is made in the range of the summary of this invention described in the claim. Is possible. Modification examples (H01) to (H04) of the present invention are exemplified below.
(H01) In each of the above embodiments, the copying machine U is illustrated as an example of the image forming apparatus, but the present invention is not limited to this. For example, the present invention can be applied to a printer as an example of an image forming apparatus, a FAX, or a multifunction machine having a plurality of functions. Further, the present invention is not limited to a single color image forming apparatus, and can be applied to a multicolor image forming apparatus. Furthermore, the present invention is not limited to the transfer belt B that holds the sheet S on the surface, and can be applied to a configuration that uses an intermediate transfer belt.

(H02) In the above-described embodiment, the configuration of the transport roll Ra disposed on the upstream side of the registration roll Rr is exemplified, but the present invention is not limited to this. For example, the present invention can be applied to any transport roll capable of transporting a medium, such as a transport roll on the downstream side of the registration roll Rr or a document transport roll in the auto-feeder U3.
(H03) Although the coil spring and the leaf spring are exemplified as the member for applying the pressing force in the above embodiment, the member is not limited to this. For example, it can be changed to an arbitrary member that applies a pressing force such as rubber or a torsion spring.

(H04) In the said Example, it is not limited to the structure which supports the follower roll 1 in the opening / closing cover U4. It is also possible to adopt a configuration in which the driving roll 2 is supported by the opening / closing cover U4. In this case, the mechanism using the coil springs 14 and 16 and the leaf springs 21 and 26 can be incorporated into the drive roll 1 side, or can be incorporated into the driven roll 1 supported by the printer unit U1. .

1 ... the main body of one of the conveying members,
1, 2 ... the main body of the conveying member,
2 ... the main body of the other conveying member,
13: Support member,
14 ... first pressing member,
16, 21 ... second pressing member,
26: pressing member,
26b ... pressing part,
Ra: Medium conveying member,
S ... medium,
SH1 ... transport path,
U: Image forming apparatus,
U1 ... recording section,
U4: Opening / closing member.

Claims (4)

A pair of conveying members disposed between the medium and conveying the medium;
A support member that supports the main body of the one transport member so as to be movable toward and away from the main body of the other transport member;
A first pressing member that applies a force to push the main body of the one transport member against the main body of the other transport member;
A second pressing member that applies a force to push the main body of the one transport member along the transport direction of the medium;
A medium conveying member comprising: A pair of conveying members disposed between the medium and conveying the medium;
A support member that supports the main body of the one transport member so as to be movable toward and away from the main body of the other transport member;
A pressing portion extending in a direction in which the main body of the one transport member is pressed against the main body of the other transport member and in a direction inclined with respect to the transport direction of the medium, and the main body of the one transport member is A pressing member that exerts a force having a component in a direction to be pressed against the main body of the transport member and a component along the transport direction of the medium, and is against the rotation center of the main body of the other transport member When the rotation center of the main body of the one transport member moves away from the main body, the pressing portion elastically deforms in a direction approaching the state along the transport direction of the medium, and the one of the transport members is elastically restored by the elastic restoring force. The pressing member that increases the force of the component in the direction in which the main body of the transport member is directed toward the main body of the other transport member;
A medium conveying member comprising: The medium conveying member according to claim 1 or 2,
A recording unit for recording an image on a medium conveyed by the medium conveying member;
An image forming apparatus comprising: A transport path through which the medium is transported;
An opening / closing member movable between an open position for opening the conveyance path to the outside and a closing position for closing the conveyance path;
A main body of the one conveying member supported by the opening and closing member;
A main body of the other transport member supported by the main body of the image forming apparatus;
The image forming apparatus according to claim 3, further comprising:

Images