JP2010113271A - Intermediate transfer device, transfer device, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stabilize rotation of an intermediate transfer body before and after the movement of an intermediate transfer body relative to an image holder. <P>SOLUTION: The intermediate transfer device (BM) includes: an endless belt-like intermediate transfer body (B); primary transfer members (T1g to T1k) that primarily transfer images held on the corresponding image holders (Pg to Pk) onto the external surface of the intermediate transfer body (B); contact/separation intermediate transfer body support members (R1 to R5) supported so as to be movable between the contact position where the intermediate transfer body (B) is brought into contact with the image holders (Pg to Pk) and the separation position where the intermediate transfer body (B) is separated from the image holders (Pg to Pk); an electricity removal member (JB) that removes electricity from the back of the intermediate transfer body (B); and linking members (LN1 to LN5) that move the electricity removal member (JB) in the moving direction of the intermediate transfer body (B) linking with the movement of the intermediate transfer body (B) according to the movement between the contact position and separation position of the contact intermediate transfer body support members (R1 to R5). <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an intermediate transfer device, a transfer device, and an image forming apparatus.

  2. Description of the Related Art Conventionally, in an image forming apparatus such as an electrophotographic copying machine or printer, a visible image formed on the surface of a photosensitive member is primarily transferred to an intermediate transfer member such as an intermediate transfer belt, and then secondary transferred from the intermediate transfer member to a medium. Regarding the image forming apparatus for fixing after transfer, the techniques described in the following Patent Documents 1 to 3 are conventionally known.

  In Japanese Patent Application Laid-Open No. 02-256083 as Patent Document 1, it is arranged on the back side of the transfer belt (5) that contacts the photosensitive drum (1A to 4A) and faces the photosensitive drum (1A to 4A). A technique for an image forming apparatus having a transfer charger (1C to 4C) and a backup roller (11) for supporting the transfer belt (5) from the back surface adjacent to the transfer charger (1C to 4C) is described. Yes. In Patent Document 1, the metal roller (11) and the transfer belt (5) are used when the metal roller (11) made of metal capable of increasing the cylindricity is used as the backup roller (11). 2 to 3 mm from the front surface or the back surface of the transfer belt (5) in order to reduce the disturbance or scattering of the toner image on the transfer belt (5) due to a local electric field generated between the transfer belt and the transfer belt. An electric field stabilizer (12, 15) made of a conductive material such as metal is supported at a distant position.

  Japanese Patent Laid-Open No. 05-10057 as Patent Document 2 is arranged on the back side of the transfer belt (5) that contacts the photosensitive drum (1A to 4A) and faces the photosensitive drum (1A to 4A). The transfer charger (1C to 4C), the backup roller (15) adjacent to the transfer charger (1C to 4C), the photosensitive drums (1A to 4A), the transfer charger (1C to 4C) and the backup roller. (15) describes a technique regarding an image forming apparatus having a backup member (12, 13) disposed between the two. In Patent Document 2, due to corona discharge of the transfer charger (1C to 4C), low-resistance foreign matter such as nitrogen oxide (NOx) adhering to the back surface of the transfer belt (5) is slid on the backup roller (15). The technology to be removed is described. Further, the toner image on the transfer belt (5) is disturbed or scattered by a local electric field generated between the backup roller (15) and the backup members (12, 13) and the transfer belt (5). In order to reduce this, the surface of each member (12, 13, 15) is composed of an insulating layer (14) such as polycarbonate.

  Furthermore, in Japanese Patent Application Laid-Open No. 09-120216 as Patent Document 3, conductive nonwoven fabrics (24 to 26, 31) and static elimination brushes (27 to 29, 32, 41 to 44) are arranged on the transfer belt (15). Thus, there is described a technique for removing charges on both the front and back surfaces of the transfer belt (15).

JP-A-02-256083 (page 2, upper left column, line 1 to lower left column, line 16; page 4, upper left column, line 5 to lower left column, line 16; page 5, upper left column, line 15) Line to lower right column, line 16, FIGS. 1 to 9) Japanese Patent Laid-Open No. 05-10057 (abstract, “0012” to “0029”, FIGS. 1 to 4) Japanese Unexamined Patent Publication No. 09-120216 (Abstract, “0024” to “0027”, FIG. 1)

  It is a technical object of the present invention to stabilize the rotation of the intermediate transfer member before and after the movement of the intermediate transfer member relative to the image carrier.

In order to solve the technical problem, an intermediate transfer apparatus according to claim 1 is provided.
An endless belt-shaped intermediate transfer member, the outer surface of which is disposed opposite to an image holding member for holding an image;
An image disposed on the back surface side of the intermediate transfer member and disposed in a primary transfer region facing the image carrier through the intermediate transfer member and holding the image held on the image carrier is an outer surface of the intermediate transfer member A primary transfer member for primary transfer thereon;
An intermediate transfer member support member for contact and separation, which is disposed on the back side of the intermediate transfer member and supports the intermediate transfer member from the back side, and a contact position where the intermediate transfer member is brought into contact with the image carrier; A separating position for separating the transfer body from the image holding body, and the intermediate transfer body supporting member for contact and separation supported so as to be movable between;
A neutralizing member disposed on the back side of the intermediate transfer body, for neutralizing charges on the back side of the intermediate transfer body;
In conjunction with the movement of the intermediate transfer body in accordance with the movement between the contact position and the separation position of the contact / separation intermediate transfer body support member, the contact / separation direction is the movement direction of the intermediate transfer body. An interlocking member that moves the static elimination member;
It is provided with.

The invention according to claim 2 is the intermediate transfer apparatus according to claim 1,
The interlocking member that moves the static elimination member with the same movement amount as the movement amount of the intermediate transfer member;
It is provided with.

The invention according to claim 3 is the intermediate transfer device according to claim 1 or 2,
The interlocking member that moves the primary transfer member in the contact / separation direction in conjunction with the movement of the intermediate transfer member;
It is provided with.

In order to solve the technical problem, an intermediate transfer device according to a fourth aspect of the present invention provides:
An endless belt-shaped intermediate transfer member, the outer surface of which is disposed opposite to an image holding member for holding an image;
Arranged on the back side of the intermediate transfer member and in a primary transfer region facing the image carrier through the intermediate transfer member, supporting the intermediate transfer member from the back side and being held by the image carrier. A primary transfer member for primary transfer of the transferred image onto the outer surface of the intermediate transfer member, the contact position where the intermediate transfer member is brought into contact with the image carrier, and the intermediate transfer member from the image carrier. The primary transfer member supported movably between a separation position to be separated; and
A neutralizing member disposed on the back side of the intermediate transfer body, for neutralizing charges on the back side of the intermediate transfer body;
The neutralization member is moved in the contact / separation direction that is the movement direction of the intermediate transfer body in conjunction with the movement of the intermediate transfer body in accordance with the movement of the primary transfer member between the contact position and the separation position. An interlocking member to be
It is provided with.

In order to solve the technical problem, the transfer device according to claim 5
5. The intermediate transfer device according to claim 1, wherein the image is primarily transferred onto an outer surface of an endless belt-shaped intermediate transfer member that is disposed so that the outer surface faces an image holding member that holds an image;
A final transfer member for transferring an image transferred onto the outer surface of the intermediate transfer member to a final transfer member;
It is provided with.

In order to solve the technical problem, an image forming apparatus according to a sixth aspect of the present invention includes:
An image carrier on which a latent image is formed on the surface;
A developing device for developing the latent image on the surface of the image carrier into an image as a visible image;
The transfer device according to claim 5, wherein the image on the surface of the image carrier is transferred to a medium;
A fixing device for fixing an image on the surface of the medium;
It is provided with.

  According to the first, fourth, fifth, and sixth aspects of the invention, the intermediate transfer member is not rotated before and after the movement of the intermediate transfer member relative to the image holding member as compared with the case where the configuration of the present invention is not provided. It can reduce becoming stable.

According to the second aspect of the present invention, the relative position between the intermediate transfer member and the charge removal member can be stabilized so that the charge removal efficiency of the charge removal member is not changed, and the configuration of the present invention is not provided. Compared to the case, it is possible to reduce image defects due to variations in charged charge and electric field on the back surface of the intermediate transfer member.
According to the third aspect of the present invention, the intermediate transfer member and the image holding member can be reliably separated.

Next, specific examples of embodiments of the present invention (hereinafter referred to as examples) will be described with reference to the drawings, but 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 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 overall explanatory view of an image forming apparatus according to Embodiment 1 of the present invention.
In FIG. 1, an image forming apparatus U according to the first exemplary embodiment includes a user interface UI as an example of an operation unit, an image input apparatus U1 as an example of an image information input apparatus, a paper feeding apparatus U2, an image forming apparatus main body U3, and a sheet. It has a processing unit U4.

The user interface UI includes a copy start key as an example of an image formation start button, a copy number setting key as an example of an image formation number setting button, an input button such as a numeric keypad as an example of a numeric input button, and a display UI1. is doing.
The image input device U1 includes an automatic document feeder and an image scanner as an example of an image reading device. In FIG. 1, an image input device U1 reads a document (not shown), converts it into image information, and inputs the image information to the image forming apparatus body U3.
The sheet feeding device U2 takes out sheet feeding trays TR1 to TR4 as an example of a plurality of sheet feeding units, a final transfer body accommodated in each of the sheet feeding trays TR1 to TR4, and a recording sheet S as an example of a medium. A sheet feeding path SH1 and the like for conveyance to the image forming apparatus main body U3 are provided.

In FIG. 1, an image forming apparatus main body U3 includes an image recording unit that records an image on a recording sheet S conveyed from the sheet feeding device U2, a toner dispenser device U3a as an example of a developer supply device, and a sheet conveyance path SH2. , A paper discharge path SH3, a paper reversal path SH4, a paper circulation path SH6, and the like. The image recording unit will be described later.
The image forming apparatus main body U3 includes a control unit C, a laser drive circuit D as an example of a latent image writing device drive circuit controlled by the control unit C, and a power supply circuit E controlled by the control unit C. Etc. The laser drive circuit D previously receives laser drive signals corresponding to image information of G: green, O: orange, Y: yellow, M: magenta, C: cyan, and K: black input from the image input device U1. At a set time, so-called timing, the image is output to the latent image forming devices ROSg, ROSo, ROSi, ROSm, ROSc, and ROSK of each color.

  Below the latent image forming apparatuses ROSg to ROSk of the respective colors, an image forming unit drawing member U3b is drawn to the front of the image forming apparatus main body U3 by a pair of left and right guide members R1 and R1, and the image forming apparatus. It is supported so as to be movable between the mounting position mounted inside the main body U3. The image forming unit pull-out member U3b includes image holding units UG, UO, UY, UM, UC, UK for the respective colors, and developing units GG, GO, GY, GM, GC, GK for the respective colors as an example of the developing device. And have. The image forming unit drawing member U3b is detachably mounted with the image carrier units UG to UK and the developing units GG to GK.

  The black image carrier unit UK includes a photosensitive drum Pk as an example of an image carrier, a charger CCk, and a cleaner CLk as an example of an image carrier cleaner. Further, a developing roll R0 as an example of a developing member of the black developing device GK is adjacent to the right side of the photosensitive drum Pk. The image holding units UG to UC of the other colors are also provided with the photosensitive drums Pg, Po, Py, Pm, Pc, chargers CCg, CCo, CCy, CCm, CCc, cleaners CLg, CLo, CLy, CLm, CLc. have. A developing roll R0 as an example of a developing member of each color developing device GG to GC is adjacent to the right side of each of the photosensitive drums Pg to Pc.

In Example 1, the K photosensitive drum Pk, which is frequently used and has a lot of surface wear, is configured to have a larger diameter than the photosensitive drums Pg to Pc of other colors, and is capable of high-speed rotation and has a long service life. Has been changed.
Visible image forming members (UG + GG), (UO + GO), (UY + GY), (UM + GM), (UC + GC), (UK + GK) are constituted by the image carrier units UY to UO and the developing units GY to GO. ing.

  In FIG. 1, the photosensitive drums Pg to Pk are uniformly charged by the chargers CCg to CCk, respectively, and then a laser beam Lg as an example of the latent image writing light output from the latent image forming devices ROSg to ROSK. , Lo, Ly, Lm, Lc, and Lk form an electrostatic latent image on the surface. The electrostatic latent images on the surfaces of the photosensitive drums Pg to Pk are developed by the developing units GG to GK, and images of G: green, O: orange, Y: yellow, M: magenta, C: cyan, K: black, The toner image is developed as an example of a visible image.

The toner images on the surfaces of the photosensitive drums Pg to Pk are primary transfer rolls T1g and T1o as an example of a primary transfer member in the primary transfer regions Q3g, Q3o, Q3y, Q3m, Q3c, and Q3k set below. , T1y, T1m, T1c, and T1k are sequentially transferred onto an intermediate transfer belt B as an example of an intermediate transfer member, and a multicolor image, so-called color image, is formed on the intermediate transfer belt B. The color image formed on the intermediate transfer belt B is conveyed to the secondary transfer area Q4.
In the case of only black image data, only the black photosensitive drum Pk and the developing device GK are used, and only a black toner image is formed.
After the primary transfer, the residual toner on the surfaces of the photosensitive drums Pg to Pk is cleaned by the cleaners CLg to CLk for the photosensitive drums.

FIG. 2 is an overall explanatory view of the belt module according to the first embodiment of the present invention.
1 and 2, below the image forming unit drawing member U3b, an intermediate transfer member drawing member U3c is drawn to the front of the image forming apparatus main body U3 and inside the image forming apparatus main body U3. It is supported so as to be movable between the mounting positions mounted on the. By the intermediate transfer member pull-out member U3c, the belt module BM as an example of an intermediate transfer device is positioned between a raised position where the belt module BM contacts the lower surface of each of the photosensitive drums Pg to Pk and a lowered position separated downward from the lower surface. It is supported so that it can be raised and lowered.

  The belt module BM has the intermediate transfer belt B. The intermediate transfer belt B is rotationally driven in the direction of the arrow Ya by a belt drive roll Rd as an example of an intermediate transfer body drive member that supports the intermediate transfer belt B from the back surface, and is driven by a tension roll Rt as an example of a tension applying member. It is stretched with tension. The intermediate transfer belt B includes a walking roll Rw as an example of a meandering prevention member for preventing meandering of the intermediate transfer belt B, a plurality of idler rolls Rf as an example of a driven member, and a secondary transfer counter member. The back side is supported by a backup roll T2a as an example.

  In the first exemplary embodiment, the intermediate transfer belt B is disposed on the upstream side of the G-color primary transfer roll T1g in the direction of the arrow Ya in a direction perpendicular to the direction of the arrow Ya and the photosensitive drum Pg. A first retracting roll R1 as an example of a contact / separation intermediate transfer member support member supported so as to be movable in a contact / separation direction, which is a direction of contact / separation, is disposed. Further, on the downstream side in the arrow Ya direction of each O-color primary transfer roll T1o and on the upstream side in the arrow Ya direction of each Y-color primary transfer roll T1y, the contact configured similarly to the first retract roll R1 is provided. A second retract roll R2 and a third retract roll R3, which are examples of the separating intermediate transfer member support member, are arranged side by side. Further, on the downstream side in the arrow Ya direction of each primary transfer roll T1c for C color and on the upstream side in the arrow Ya direction for each primary transfer roll T1k for K color, the contact configured similarly to the first retract roll R1 is provided. A fourth retract roll R4 as an example of a separating intermediate transfer member support member is disposed. Further, a fifth retract roll as an example of the intermediate transfer member support member for contact / separation configured similarly to the first retract roll R1 is provided downstream of the K primary transfer rolls T1k in the direction of the arrow Ya. R5 is arranged.

Further, on the downstream side in the direction of the arrow Ya of each of the primary transfer rolls T1g to T1k, a plate-shaped discharge sheet metal JB as an example of a discharge member that discharges the charge on the back surface of the intermediate transfer belt B is disposed. In addition, the said neutralization sheet metal JB of Example 1 is arrange | positioned in the non-contact with the said intermediate transfer roll B, for example, can be arrange | positioned in the position 2 mm away from the back surface of the said intermediate transfer roll B.
Belt support rolls Rd, Rt, Rw, Rf as an example of an intermediate transfer member support member that rotatably supports the intermediate transfer belt B from the back surface by the rolls Rd, Rt, Rw, Rf, T2a, R1 to R5. , T2a, R1 to R5.
Further, the belt module according to the first embodiment includes the intermediate transfer belt B, the belt support rolls Rd, Rt, Rw, Rf, T2a, R1 to R5, the primary transfer rolls T1g to T1k, the static elimination sheet metal JB, and the like. A BM is configured.

A secondary transfer unit Ut is disposed below the backup roll T2a. A secondary transfer roll T2b as an example of a secondary transfer member of the secondary transfer unit Ut is disposed so as to be separated from and contactable with the backup roll T2a with the intermediate transfer belt B interposed therebetween. The secondary transfer roll T2b is A secondary transfer region Q4 is formed by the region in pressure contact with the intermediate transfer belt B. The backup roll T2a is in contact with a contact roll T2c as an example of a voltage application contact member, and each of the rolls T2a to T2c constitutes a secondary transfer device T2 as an example of a final transfer member. .
A secondary transfer voltage having the same polarity as the charging polarity of the toner is applied to the contact roll T2c at a preset timing from a power supply circuit controlled by the control unit C.

A sheet conveyance path SH2 is disposed below the belt module BM. The recording sheet S fed from the sheet feeding path SH1 of the sheet feeding device U2 is conveyed to the sheet conveying path SH2, and a toner image is transferred to the secondary transfer region Q4 by a registration roll Rr as an example of a sheet feeding timing adjusting member. At the same time, it is conveyed to the secondary transfer region Q4 through the medium guide member SGr and the pre-transfer medium guide member SG1.
The medium guide member SGr is fixedly supported by the image forming apparatus main body U3 together with the registration roll Rr.
The toner image on the intermediate transfer belt B is transferred to the recording paper S by the secondary transfer device T2 when passing through the secondary transfer region Q4. In the case of a full-color image, the toner images primarily transferred onto the surface of the intermediate transfer belt B are secondarily transferred onto the recording paper S all at once.

The intermediate transfer belt B after the secondary transfer is cleaned, that is, cleaned by a belt cleaner CLB as an example of an intermediate transfer body cleaner. The secondary transfer roll T2b and the belt cleaner CLB are supported so as to be separated from and in contact with the intermediate transfer belt B.
The belt module BM, the secondary transfer device T2, the belt cleaner CLB, and the like constitute a transfer device TS that transfers images on the surfaces of the photosensitive drums Py to Po to the recording paper S.

The recording sheet S on which the toner image is secondarily transferred is conveyed to the fixing device F through a post-transfer medium guide member SG2 and a sheet conveyance belt BH as an example of a medium medium member before fixing. The fixing device F has a heating roll Fh as an example of a heat fixing member and a pressure roll Fp as an example of a pressure fixing member, and is fixed by a region where the heating roll Fh and the pressure roll Fp are in pressure contact with each other. Region Q5 is formed.
The toner image on the recording paper S is heated and fixed by the fixing device F when passing through the fixing region Q5. A transport path switching member GT1 is provided on the downstream side of the fixing device F. The conveyance path switching member GT1 selectively selects the recording sheet S conveyed through the sheet conveyance path SH2 and heated and fixed in the fixing region Q5, either on the sheet discharge path SH3 or the sheet reversing path SH4 side of the sheet processing apparatus U4. Switch. The recording sheet S conveyed to the sheet discharge path SH3 is conveyed to the sheet conveyance path SH5 of the sheet processing apparatus U4.

  A curl correction device U4a is disposed in the middle of the sheet conveyance path SH5, and a switching gate G4 as an example of a conveyance path switching member is disposed in the sheet conveyance path SH5. The switching gate G4 causes the first curl correction member h1 or the second curl correction member h2 to move the recording sheet S conveyed from the sheet conveyance path SH3 of the image forming apparatus main body U3 according to the direction of curving, so-called curl. Transport to either side of The recording paper S conveyed to the first curl correction member h1 or the second curl correction member h2 is curled when passing. The recording sheet S with the curl corrected is in a so-called face-up state in which the image fixing surface of the sheet faces upward from a discharge roll Rh as an example of a discharge member to a discharge tray TH1 as an example of a discharge unit of the paper processing device U4. It is discharged at.

The recording sheet S transported to the sheet reversing path SH4 side of the image forming apparatus main body U3 by the transport path switching member GT1 pushes the transport direction regulating member constituted by an elastic thin film member, so-called mylar gate GT2. Passed and conveyed to the sheet reversing path SH4 of the image forming apparatus main body U3.
A sheet circulation path SH6 and a sheet reversing path SH7 are connected to the downstream end of the sheet reversing path SH4 of the image forming apparatus main body U3, and a mylar gate GT3 is also disposed at the connecting portion. The recording sheet S conveyed to the sheet conveying path SH4 through the switching gate GT1 passes through the mylar gate GT3 and is conveyed to the sheet reversing path SH7 side of the sheet processing apparatus U4. When performing duplex printing, the recording paper S that has been transported through the paper reversing path SH4 passes through the Mylar gate GT3 as it is, is transported to the paper reversing path SH7, and then transported in the opposite direction. When switched back, the transport direction is regulated by the Mylar gate GT3, and the switched recording sheet S is transported to the sheet circulation path SH6. The recording sheet S conveyed to the sheet circulation path SH6 is retransmitted to the transfer area Q4 through the sheet feeding path SH1.

On the other hand, when the recording paper S conveyed on the paper reversing path SH4 is switched back after the trailing edge of the recording paper S passes through the Mylar gate GT2 and before passing through the Mylar gate GT3, the Mylar gate GT2 causes the recording paper S The transport direction is regulated, and the recording paper S is transported to the paper transport path SH5 with the front and back sides reversed. After the curling of the recording paper S with the front and back reversed is corrected by the curl correction member U4a, the image fixing surface of the recording paper S faces downward in the paper discharge tray TH1 of the paper processing device U4, so-called face down. It can be discharged in a state.
A sheet transport path SH is constituted by the elements indicated by the symbols SH1 to SH7. Further, the sheet conveying device SU is constituted by the elements indicated by the symbols SH, Ra, Rr, Rh, SGr, SG1, SG2, BH, GT1 to GT3.

(Description of links LN1 to LN5)
FIG. 3 is an enlarged explanatory view of the main part of the first link of the first embodiment of the present invention, FIG. 3A is an explanatory diagram of the state of the first link when the first retract roll is moved to the contact position, and FIG. It is state explanatory drawing of the 1st link when a 1st retract roll moves to a separation position.
In FIG. 3, the rotation shaft 1 of the first retract roll R <b> 1 according to the first embodiment has first guide grooves 2 extending in the contact / separation direction formed in frames (not shown) arranged at both front and rear ends of the belt module BM. It is supported so as to be rotatable in a penetrating state. That is, the first retracting roll R1 of the first embodiment is supported so as to be movable in the contact / separation direction when the rotating shaft 1 is guided by the first guide groove 2.

  The rotation shaft 3 of the G primary transfer roll T1g is supported by a pressing member 4 extending in the contact / separation direction supported by the frame of the belt module BM. The pressing member 4 according to the first embodiment includes a pedestal portion 4a supported by the frame body. An elastic body accommodating space 4b extending in the contact / separation direction is formed inside the base portion 4a. A bearing portion 4c that rotatably supports the rotating shaft 3 is disposed on the side of the intermediate transfer belt B of the pedestal portion 4a, and the elastic body accommodating space 4b is disposed on the lower surface of the bearing portion 4c. An elastic body penetrating support portion 4d extending inward is formed. Further, between the pedestal portion 4a and the bearing portion 4c, a pressing spring 4e as an example of an elastic body is accommodated in the elastic body accommodating space 4b of the pedestal portion 4a and penetrates through the elastic body of the bearing portion 4c. It is mounted in a state of being penetrated by the support portion 4d. That is, the G-color primary transfer roll T1g of Example 1 is moved toward the intermediate transfer belt B by the pressing spring 4e that can be expanded and contracted along the elastic body accommodating space 4b and the elastic body penetration support portion 4d. It is supported so as to be movable in the approaching / separating direction in the biased state.

  Further, at both ends of the static elimination sheet metal JB in the direction of the arrow Ya, projections 6 and 7 projecting outward from both front and rear end parts of the static elimination sheet metal JB are formed. The second guide groove 8 and the third guide groove 9 extending in the contact / separation direction formed in the frame of the module BM are supported in a state of penetrating each other. That is, the static elimination sheet metal JB of Example 1 is supported so as to be movable in the contact / separation direction by the projections 6 and 7 being guided by the guide grooves 8 and 9.

  Further, below the first retracting roll R1, the G primary transfer roll T1g, and the neutralizing sheet metal JB, the downstream side of the neutralizing sheet metal JB in the direction of the arrow Ya from the upstream side of the first retracting roll R1 in the direction of the arrow Ya. A link main body 11 as an example of an interlocking member main body that extends to the side and is movable in the arrow Ya direction is disposed. A first engaged portion 11a extending toward the intermediate transfer belt B is formed at the upstream end of the link main body 11 in the arrow Ya direction according to the first exemplary embodiment. The link body 11 extends toward the intermediate transfer belt B at a position corresponding to the downstream side in the arrow Ya direction of the first retracting roll R1 and the upstream side in the arrow Ya direction of the primary transfer roll T1g for G color. A second engaged portion 11b is formed in parallel with the first engaged portion 11a. The link main body 11 has a first connecting shaft 11c and a second connecting shaft at positions corresponding to the downstream side in the arrow Ya direction of the G-color primary transfer roll T1g and the downstream side in the arrow Ya direction of the static elimination sheet metal JB. 11d is formed on each of the connecting shafts 11c and 11d. The first interlocking arm 12 and the second interlocking arm 13 as an example of a first arm part and a second arm part extending to the intermediate transfer belt B side. Is rotatably supported.

The central portions of the interlocking arms 12 and 13 of the first embodiment are rotatably supported by a first rotating shaft 12a and a second rotating shaft 13a supported by the frame body of the belt module BM. Further, a first contact portion 12b is formed at the upper end portion of the first interlocking arm 12 so as to extend upstream in the direction of the arrow Ya and to contact the rotary shaft 3 from above. Further, a second contact portion 13b is formed at the lower end portion of the second interlocking arm 13 so as to extend upstream in the direction of the arrow Ya and to contact the static elimination sheet metal JB from below.
Further, an eccentric cam 14 as an example of an eccentric rotating member is disposed between the engaged portions 11a and 11b. The eccentric cam 14 of the first embodiment is formed in a disk shape in cross section, and the rotation center 14a of the eccentric cam 14 is rotatably supported by the frame body of the belt module BM.

The outer peripheral surface of the eccentric cam 14 has a first end point 14b that is the end point farthest from the rotation center 14a, and a second end point that is 90 ° away from the first end point 14b upstream in the direction of the arrow Ya. An end point 14c and a third end point 14d that is 180 ° apart from the first end point 14b and closest to the rotation center 14a are set in advance.
Here, in Example 1, as shown in FIG. 3A, when the lower end portion of the first retract roll R1 is supported while being in contact with the first end point 14b of the eccentric cam 14, The retract roll R1 is set in advance so as to move to a contact position where the intermediate transfer belt B contacts the photosensitive drum Pg.
In this case, the first engaged portion 11a of the link main body 11 is engaged with the eccentric cam 14 at the second end point 14c disposed at the upstream end portion in the arrow Ya direction of the eccentric cam 14. Supported by the state.

  Further, when the eccentric cam 14 is rotated in the direction of the arrow Yb from the state shown in FIG. 3A, the end point supporting the lower end portion of the first retract roll R1 moves, and as shown in FIG. 3B, the eccentric cam 14 It will be in the state supported in the state which contacted 14 2nd end point 14c vicinity. In this case, the first retracting roll R1 is set in advance such that the intermediate transfer belt B is moved to a separation position where the intermediate transfer belt B is separated from the photosensitive drum Pg by tension or weight. At this time, the second engaged portion 11b of the link body 11 is pressed against the outer peripheral surface of the eccentric cam 14 and moves downstream in the direction of the arrow Ya.

As the connecting shafts 11c and 11d move downstream in the direction of arrow Ya, the interlocking arms 12 and 13 are arrows that are opposite to the direction of arrow Yb with the rotation shafts 12a and 13a as the center of rotation. Rotate in Yc direction. Therefore, as shown in FIG. 3B, the contact portions 12b and 13b rotate and move toward the link body 11 side. Therefore, the G-color primary transfer roll T1g is pressed from above by the first contact portion 12b and moves toward the link body 11 against the pressing force of the pressing spring 4e. Further, the static elimination sheet metal JB also moves toward the link main body 11 by its own weight from the state in which the lower surface is supported by the upper ends of the guide grooves 8 and 9 by the second contact portion 13b.
Accordingly, the first retracting roll R1, the G primary transfer roll T1g, and the static eliminating sheet metal JB move in a direction away from the photosensitive drum Pg, and the intermediate transfer belt B moves to the photosensitive drum. Leave Pg.

  When the eccentric cam 14 is rotated in the direction of the arrow Yc from the state shown in FIG. 3B, that is, when the eccentric cam 14 is rotated in the reverse direction, the end point supporting the lower end portion of the first retract roll R1 moves, and FIG. As shown in FIG. 4, the eccentric cam 14 returns to the state of being supported while being in contact with the vicinity of the first end point 14b. In this case, the first retracting roll R1 returns to the contact position, contacts the intermediate transfer belt B, and lifts up. At this time, as the eccentric cam 14 rotates, the first engaged portion 11a of the link body 11 is pressed against the outer peripheral surface of the eccentric cam 14 and moves upstream in the direction of the arrow Ya.

As the connecting shafts 11c and 11d move upstream in the direction of the arrow Ya, the interlocking arms 12 and 13 are arrows that are opposite to the direction of the arrow Yc with the rotating shafts 12a and 13a as the center of rotation. Rotate in Yb direction. Therefore, as shown in FIG. 3A, the contact portions 12b and 13b rotate and move to the intermediate transfer belt B side. For this reason, the G primary transfer roll T1g is released to the intermediate transfer belt B side by the pressing force of the pressing spring 4e when the pressure of the first contact portion 12b is released, and the intermediate transfer belt B Is pressed against the photosensitive drum Pg. Further, the lower surface of the static elimination sheet metal JB is also lifted upward by the second contact portion 13b.
The movement of the intermediate transfer belt B according to the movement between the contact position and the separation position of the first retracting roll R1 by the link main body 11, the interlocking arms 12, 13, the eccentric cam 14, and the like, A first link LN1 as an example of an interlocking member that interlocks the movement of the G-color primary transfer roll T1g and the static eliminating sheet metal JB is configured.
In the first link LN1 of Example 1, the amount of movement of the intermediate transfer belt B by the first retracting roll R1, the G primary transfer roll T1g, and the like, and the amount of movement of the charge removal sheet metal JB are as follows. It is preset to be the same.

  Further, the first link is between the second retract roll R2 and the O-color primary transfer roll T1o disposed on the upstream side in the arrow Ya direction of the second retract roll R2 and the neutralizing sheet metal JB. A second link LN2 as an example of the interlocking member configured similarly to LN1 is disposed. In addition, the third retract roll R3, the Y primary transfer roll T1y disposed downstream of the third retract roll R3 in the direction of the arrow Ya, the M primary transfer roll T1m, and the static elimination Between the sheet metal JB, a third link LN3 as an example of the interlocking member configured similarly to the links LN1 and LN2 is disposed.

Further, each link LN1 is provided between the fourth retract roll R4 and the C-color primary transfer roll T1c disposed on the upstream side in the arrow Ya direction of the fourth retract roll R4 and the neutralizing sheet metal JB. The 4th link LN4 as an example of the said interlocking member comprised similarly to -LN3 is arrange | positioned. Further, each link LN1 is provided between the fifth retract roll R5 and the K-color primary transfer roll T1k and the neutralizing sheet metal JB arranged on the upstream side in the arrow Ya direction of the fifth retract roll R5. A fifth link LN5 as an example of the interlocking member configured similarly to LN4 is disposed.
Since the first link LN1 and the other links LN2 to LN5 have the same configuration, a detailed description of the links LN2 to LN5 is omitted.

FIG. 4 is an enlarged explanatory view of a change in the shape of the belt module according to the first embodiment of the present invention. FIG. 4 is an explanatory view showing a state where the G and O photoconductor drums are separated from the intermediate transfer belt from the state shown in FIG.
FIG. 5 is an enlarged explanatory view of a change in the shape of the belt module according to the first embodiment of the present invention, and is an explanatory view showing a state in which the Y and M photoconductor drums are separated from the intermediate transfer belt from the state of FIG.
FIG. 6 is an enlarged explanatory view of the shape change of the belt module according to the first embodiment of the present invention, and is an explanatory view in a state in which the photosensitive drums of all colors except the K color are separated from the intermediate transfer belt from the state of FIG. is there.
Therefore, in the belt module BM according to the first embodiment, for example, as illustrated in FIG. 2, when the toners of six colors G, O, Y, M, C, and K are used, the links LN <b> 1 to LN <b> 1. The retract rolls R1 to R5 and the primary transfer rolls T1g to T1k are moved to contact positions by the LN5, and the photosensitive drums Pg to Pk are brought into contact with the intermediate transfer belt B.

For example, as shown in FIG. 4, when toners of four colors Y, M, C, and K are used, the retract rolls are moved from the state shown in FIG. 2 by the links LN1 and LN2. R1 and R2 and the primary transfer rolls T1g and T1o are moved from the contact position to the separation position, and the intermediate transfer belt B is separated from the photosensitive drums Pg and Po. For example, as shown in FIG. 6, when only the K color toner is used, the retract rolls R <b> 1 to R <b> 4 and the respective ones are moved from the state shown in FIG. 2 through the links LN <b> 1 to LN <b> 4. The next transfer rolls T1g to T1c are moved from the contact position to the separation position, and the intermediate transfer belt B is separated from the photosensitive drums Pg to Pc other than the K-color photosensitive drum Pk.
Incidentally, as shown in FIG. 5, it is possible to use toners of four colors G, O, C, and K. In this case, from the state shown in FIG. 2, the third link LN3 The third retract roll R3 and the primary transfer rolls T1y and T1m are moved from the contact position to the separation position, and the intermediate transfer belt B is separated from the photosensitive drums Py and Pm.

(Operation of Example 1)
In the image forming apparatus U of Embodiment 1 of the present invention having the above-described configuration, when an image forming operation, so-called job, is executed, each color supplied to the developing roll R0 of each of the developing devices GG to GK. The electrostatic latent images on the surfaces of the photosensitive drums Pg to Pk are developed with the toner. The toner images on the surfaces of the photosensitive drums Pg to Pk are sequentially transferred onto the intermediate transfer belt B by primary transfer by the primary transfer rolls T1g to T1k in the primary transfer regions Q3g to Q3k. As a result, a color image is formed. Then, the color image formed on the intermediate transfer belt B is conveyed to the secondary transfer region Q4 and secondarily transferred onto the recording paper S by the secondary transfer unit T2.

Here, in the belt module BM according to the first exemplary embodiment, a plate-shaped discharge sheet metal JB as an example of the discharge member is disposed in a non-contact manner on the downstream side in the arrow Ya direction of each of the primary transfer rolls T1g to T1k. The charge on the intermediate transfer belt B is neutralized. For this reason, the toner image on the intermediate transfer belt B is prevented from being disturbed or scattered by being locally charged by the discharge of the primary transfer rolls T1g to T1k or the like.
Further, in the belt module BM of the first embodiment, as shown in FIGS. 4 to 6, the movement between the contact positions and the separation positions of the retract rolls R1 to R5 and the primary transfer rolls T1g to T1k is performed. Thus, the photosensitive drums Pg to Pk and the intermediate transfer belt B can be brought into contact with or separated from each other. For this reason, it is possible to reduce the wear deterioration of the members Pg to Pk, B by separating the intermediate transfer belt B from the photosensitive drums Pg to Pk that are not used in the first embodiment.

Further, in the belt module BM according to the first embodiment, as shown in FIG. 3, the links LN1 to LN5 move the retract rolls R1 to R5 and the primary transfer rolls T1g to T1k, and the static eliminator. The movement of the sheet metal JB is linked.
Here, in the technique described in Patent Documents 1 to 3 in which the static eliminating sheet metal JB does not move in accordance with the movement of the rolls R1 to R5, T1g to T1k, the rolls R1 to R5, T1g to The distance between the neutralization sheet metal JB and the intermediate transfer belt B changes due to the movement between the contact position and the separation position of T1k.

That is, in the conventional configuration in which the static eliminating sheet metal JB does not move, when each of the rolls R1 to R5 and T1g to T1k moves to the separation position, the distance becomes short, or the neutralizing sheet metal JB and the intermediate transfer belt. B comes into contact. In this case, for example, the neutralization sheet metal JB may excessively neutralize the intermediate transfer belt B. Further, in the conventional configuration in which the static eliminating sheet metal JB does not move, when the rolls R1 to R5 and T1g to T1k move to the contact position, the distance becomes long. In this case, for example, there is a possibility that the intermediate transfer belt B is not sufficiently discharged by the discharging sheet metal JB.
As a result, the neutralization efficiency of the neutralization sheet metal JB changes due to the movement of each of the rolls R1 to R5, T1g to T1k, so the charged charge and electric field on the back surface of the intermediate transfer belt B are not stable, and so-called variation occurs. To do. Therefore, the toner image on the intermediate transfer belt B may be disturbed or scattered due to variations in the electric field or the like, and image defects may occur.

  However, in the image forming apparatus U according to the first exemplary embodiment, the static eliminating sheet metal JB moves together with the intermediate transfer belt B in conjunction with the movement between the contact positions and the separation positions of the rolls R1 to R5 and T1g to T1k. To do. In the first embodiment, the movement amount of the intermediate transfer belt B due to the movement of the rolls R1 to R5 and T1g to T1k is set in advance so as to be the same as the movement amount of the neutralizing sheet metal JB. Therefore, in the image forming apparatus U according to the first exemplary embodiment, the relative position between the intermediate transfer belt B and the neutralization sheet metal JB is stabilized by interlocking with the rolls R1 to R5 and T1g to T1k, and the neutralization sheet metal. The static elimination efficiency of JB does not change, and the occurrence of image defects due to variations in the electric field is reduced.

In the techniques of Patent Documents 1 to 3 and the like, when the static eliminating sheet metal JB is in strong contact with the intermediate transfer belt B, the conveyance resistance increases and the rotation speed of the intermediate transfer belt B in the direction of the arrow Ya decreases. MQ: Deterioration of motion quality, so-called uneven speed may occur. In this case, since the secondary transfer timing is shifted, there is a possibility that an image defect such as an image shift of the recording paper may occur.
However, in the image forming apparatus U according to the first exemplary embodiment, the neutralizing sheet metal JB and the intermediate transfer belt B are moved before and after the movement between the contact position and the separation position of the rolls R1 to R5 and T1g to T1k. However, since the non-contact state is maintained, the occurrence of image defects due to the speed unevenness is reduced.
In particular, as shown in FIG. 5, when only intermediate Y and M toners are not used, the neutralization of the neutralization sheet metal JB from the O primary transfer region Q3o to the C primary transfer region Q3c is performed. Due to the fact that the efficiency does not change and the speed nonuniformity does not occur, the effect of reducing image defects is great, and a good image can be easily formed as compared with the conventional configuration.

(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 performed within the range of the summary of this invention described in the claim. It is possible. Modification examples (H01) to (H06) of the present invention are exemplified below.
(H01) In the above embodiment, the image forming apparatus U is configured by a so-called multi-function machine, but is not limited thereto, and may be configured by, for example, a printer, a FAX, or the like.
(H02) In the embodiment, the image forming apparatus U is not limited to a configuration using six colors of toner, and may be configured to use, for example, five colors or less or seven colors or more. .

(H03) In the above embodiment, toners of six colors of G: green, O: orange, Y: yellow, M: magenta, C: cyan, and K: black are used. However, the present invention is not limited to this. : It is also possible to use toners of colors other than the above six colors instead of the green and O: orange toners. In addition, a colorless toner that coats the image surface for waterproofing and protection, and a pre-set shape and arrangement, for example, a linear magnetic wire, in the image of the printing paper to prevent theft It is also possible to use a magnetic toner. An anti-theft device for detecting a magnetic pulse generated from a magnetic wire is described in, for example, Japanese Patent Application Laid-Open No. 2006-256124, and is well known.
(H04) In the embodiment, the primary transfer rolls T1g to T1k facing the photoconductor drums Pg to Pk are arranged in the primary transfer regions Q3g to Q3k, but the invention is not limited thereto. For example, in place of the primary transfer rolls T1g to T1k, a non-contact type primary transfer corotron can be disposed. In this case, even if each of the retract rolls R1 to R5 is moved to the separated position, the corresponding retract rolls R1 to R5 are arranged in advance so that the corresponding unused primary transfer corotrons are not in contact with each other. Even if each primary transfer corotron is not interlocked with the movement of each of the static eliminating metal plates JB, the effects of the present invention can be achieved.

(H05) In the embodiment, each of the rolls R1 to R5, T1g to T1k is moved between the contact position and the separation position, and the intermediate transfer belt B and each of the photosensitive drums Pg to Pk are brought into contact with each other. For example, the retract rolls R1 to R5 are omitted, and only the primary transfer rolls T1y to T1m are moved between the contact position and the separation position. Even when the movement of the intermediate transfer belt B by the primary transfer rolls T1y to T1m and the movement of the charge eliminating sheet metal JB are interlocked, the effects of the present invention can be achieved. That is, the primary transfer rolls T1y to T1m can be provided with the functions of the retract rolls R1 to R5.
(H06) In the above embodiment, the static eliminating sheet metal JB is configured to be disposed in a non-contact manner with respect to the intermediate transfer belt B. However, the present invention is not limited to this configuration. For example, instead of the neutralizing sheet metal JB, It is also possible to adopt a configuration in which a conductive nonwoven fabric, a static elimination brush, or the like as an example of a static elimination member is brought into contact with the intermediate transfer belt B. In this case, a configuration similar to that of each of the links LN1 to LN5 is provided so that the movement of the intermediate transfer belt B and the movement of the conductive nonwoven fabric / static charge brush are interlocked. It is possible to prevent the conveyance resistance and the charge removal performance of the intermediate transfer belt B from being changed by the change or separation of the pressing force.

FIG. 1 is an overall explanatory view of an image forming apparatus according to Embodiment 1 of the present invention. FIG. 2 is an overall explanatory view of the belt module according to the first embodiment of the present invention. FIG. 3 is an enlarged explanatory view of the main part of the first link of the first embodiment of the present invention, FIG. 3A is an explanatory diagram of the state of the first link when the first retract roll is moved to the contact position, and FIG. It is state explanatory drawing of the 1st link when a 1st retract roll moves to a separation position. FIG. 4 is an enlarged explanatory view of a change in the shape of the belt module according to the first embodiment of the present invention. FIG. 4 is an explanatory view showing a state where the G and O photoconductor drums are separated from the intermediate transfer belt from the state shown in FIG. FIG. 5 is an enlarged explanatory view of a change in the shape of the belt module according to the first embodiment of the present invention, and is an explanatory view showing a state in which the Y and M photoconductor drums are separated from the intermediate transfer belt from the state of FIG. FIG. 6 is an enlarged explanatory view of the shape change of the belt module according to the first embodiment of the present invention, and is an explanatory view in a state in which the photosensitive drums of all colors except the K color are separated from the intermediate transfer belt from the state of FIG. is there.

Explanation of symbols

B ... Intermediate transfer member,
BM: Intermediate transfer device,
F: Fixing device,
GG to GK: developing device,
JB: Static elimination member,
LN1 to LN5 ... interlocking members,
Pg to Pk: Image carrier,
Q3g to Q3k ... primary transfer region,
R1-R5: Intermediate transfer member support member for contact and separation,
S ... medium,
T1g to T1k ... primary transfer member,
T2: Final transfer member,
TS ... Transfer device,
U: Image forming apparatus.

Claims (6)

An endless belt-shaped intermediate transfer member, the outer surface of which is disposed opposite to an image holding member for holding an image;
An image disposed on the back surface side of the intermediate transfer member and disposed in a primary transfer region facing the image carrier through the intermediate transfer member and holding the image held on the image carrier is an outer surface of the intermediate transfer member A primary transfer member for primary transfer thereon;
An intermediate transfer member support member for contact and separation, which is disposed on the back side of the intermediate transfer member and supports the intermediate transfer member from the back side, and a contact position where the intermediate transfer member is brought into contact with the image carrier; A separating position for separating the transfer body from the image holding body, and the intermediate transfer body supporting member for contact and separation supported so as to be movable between;
A neutralizing member disposed on the back side of the intermediate transfer body, for neutralizing charges on the back side of the intermediate transfer body;
In conjunction with the movement of the intermediate transfer body in accordance with the movement between the contact position and the separation position of the contact / separation intermediate transfer body support member, the contact / separation direction is the movement direction of the intermediate transfer body. An interlocking member that moves the static elimination member;
An intermediate transfer device comprising: The interlocking member that moves the static elimination member with the same movement amount as the movement amount of the intermediate transfer member;
The intermediate transfer apparatus according to claim 1, further comprising: The interlocking member that moves the primary transfer member in the contact / separation direction in conjunction with the movement of the intermediate transfer member;
The intermediate transfer apparatus according to claim 1, further comprising: An endless belt-shaped intermediate transfer member, the outer surface of which is disposed opposite to an image holding member for holding an image;
Arranged on the back side of the intermediate transfer member and in a primary transfer region facing the image carrier through the intermediate transfer member, supporting the intermediate transfer member from the back side and being held by the image carrier. A primary transfer member for primary transfer of the transferred image onto the outer surface of the intermediate transfer member, the contact position where the intermediate transfer member is brought into contact with the image carrier, and the intermediate transfer member from the image carrier. The primary transfer member supported movably between a separation position to be separated; and
A neutralizing member disposed on the back side of the intermediate transfer body, for neutralizing charges on the back side of the intermediate transfer body;
The neutralization member is moved in the contact / separation direction that is the movement direction of the intermediate transfer body in conjunction with the movement of the intermediate transfer body in accordance with the movement of the primary transfer member between the contact position and the separation position. An interlocking member to be
An intermediate transfer device comprising: 5. The intermediate transfer device according to claim 1, wherein the image is primarily transferred onto an outer surface of an endless belt-shaped intermediate transfer member that is disposed so that the outer surface faces an image holding member that holds an image;
A final transfer member for transferring an image transferred onto the outer surface of the intermediate transfer member to a final transfer member;
A transfer device comprising: An image carrier on which a latent image is formed on the surface;
A developing device for developing the latent image on the surface of the image carrier into an image as a visible image;
The transfer device according to claim 5, wherein the image on the surface of the image carrier is transferred to a medium;
A fixing device for fixing an image on the surface of the medium;
An image forming apparatus comprising:

Images