JP2010191051A - Transfer device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a transfer device and an image forming apparatus capable of peeling a conveyed recording medium from a conveying member, which rotates to convey the recording medium. <P>SOLUTION: Negative toner on an intermediate transfer belt 30 is transferred to a sheet member P by repulsing a supporting roll 34 to which negative voltage is applied. The sheet member P is electrified to a more positive side than the supporting roll 34. Furthermore, discharge is generated between the supporting roll 34 and a destaticizing member 42, and a surface of the destaticizing member 42 is electrified with negative charge. By electrifying the surface of the destaticizing member 42 with the negative charge, potential gradient generated between the destaticizing member 42 and the sheet member P is made nearer to potential gradient generated between the sheet member P and the supporting roll 34. Thus, the sheet member P wound around the supporting roll 34 through the intermediate transfer belt 30 is attracted to the destaticizing member 42 side and peeled from the supporting roll 34. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

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

  Patent Document 1 describes a plastic peeling claw that peels off a sheet stuck on the surface of a photosensitive drum from the surface of the photosensitive drum.

Specifically, by making the shape of the nail of the portion in contact with the photosensitive drum a predetermined shape, the paper can be peeled from the photosensitive drum without damaging the surface of the photosensitive drum. ing.
JP-A-3-245173

  An object of the present invention is to peel the conveyed recording medium from the conveying member that rotates and conveys the recording medium.

  In the transfer device according to the first aspect of the present invention, a negative voltage is applied and a conveyance member that rotates and conveys a recording medium and a recording medium that is provided facing the conveyance member and conveyed are conveyed A transfer member that is grounded and transfers a toner image to the recording medium; and a recording member that is grounded and downstream of the transfer member in a recording medium conveyance direction and conveyed to the conveyance member And a neutralizing member that is disposed on the opposite side of the sheet and disposed at a position where electric discharge can be performed between the conveying member and grounded through a resistance member.

  In the transfer device according to a second aspect of the present invention, a negative voltage is applied, and a conveyance member that rotates and conveys the recording medium, and a recording medium that is provided facing the conveyance member and is conveyed are conveyed. A transfer member that is grounded and transfers a toner image to the recording medium; and a recording member that is grounded and downstream of the transfer member in a recording medium conveyance direction and conveyed to the conveyance member And a neutralizing member that is disposed on the opposite side with respect to the substrate and disposed at a position where discharge can be performed between the conveying member and grounded through a rectifier that releases positive charges.

  According to a third aspect of the present invention, a transfer apparatus is provided with a negative voltage applied thereto, a conveyance member that rotates and conveys a recording medium, and a recording medium that is provided facing the conveyance member and is conveyed. A transfer member that is grounded and transfers a toner image to the recording medium; and a recording member that is grounded and downstream of the transfer member in a recording medium conveyance direction and conveyed to the conveyance member A rectifier that is provided on the opposite side with respect to the carrier member and is disposed at a position where discharge can be performed with the transport member, and is grounded through a rectifier that releases positive charges and a resistance member connected in parallel to the rectifier And.

  According to a fourth aspect of the present invention, in the transfer device according to the first or third aspect, the resistance member is a variable resistance member capable of changing a resistance value of the resistance member.

  The transfer device according to a fifth aspect of the present invention is the transfer device according to the first, third, or fourth aspect, wherein the guide member guides the recording medium to the conveyance member and the holding portion of the transfer member, the resistance member, and the charge removal member. A connection member for electrically connecting the guide member and a conductive member for electrically connecting the guide member and the connection member are provided.

  A transfer device according to a sixth aspect of the present invention is the transfer device according to any one of the first to fifth aspects, wherein the width direction is a direction perpendicular to the conveyance direction in which the recording medium is conveyed. The length in the width direction ≧ the length in the width direction of the static elimination member> the length in the width direction of the recording medium is satisfied.

  According to a seventh aspect of the present invention, there is provided an image forming apparatus comprising: the transfer device according to any one of the first to sixth aspects; and a fixing device that fixes a toner image transferred to a recording medium by the transfer device. It is characterized by providing.

  According to the configuration of the first aspect of the present invention, it is possible to peel the conveyed recording medium from the conveying member that rotates and conveys the recording medium, as compared with the case without this configuration.

  According to the configuration of the second aspect of the present invention, it is possible to peel the conveyed recording medium from the conveying member that rotates and conveys the recording medium, as compared with the case without this configuration.

  According to the configuration of the third aspect of the present invention, it is possible to reliably peel the conveyed recording medium from the conveying member that rotates and conveys the recording medium, as compared with the case without this configuration.

  According to the configuration of the fourth aspect of the present invention, the recording medium to be conveyed is peeled from the conveying member that rotates and conveys the recording medium even when the environment changes, as compared with the case without this configuration. Can do.

  According to the configuration of the fifth aspect of the present invention, the toner image transferred to the water-containing paper is disturbed even when the toner image is transferred to the water-containing paper having a low resistance value as compared with the case without this configuration. Can be suppressed.

  According to the structure of Claim 6 of this invention, compared with the case where it does not have this structure, the discharge which arises between a conveyance member and a static elimination member can be stabilized.

  According to the configuration of the seventh aspect of the present invention, the recording medium can be reliably conveyed to the fixing device as compared with the case where the configuration is not provided.

  An image forming apparatus employing an example of a transfer device according to a first embodiment of the present invention will be described with reference to FIGS.

(overall structure)
As shown in FIG. 3, the image forming apparatus 100 performs image processing based on color image information sent from an image data input device such as a personal computer (not shown), and a sheet as a recording medium by electrophotography. A color image is formed on the member P.

  The image forming apparatus 100 includes image forming units 10Y, 10M, 10C, and 10K that form toner images of respective colors of yellow (Y), magenta (M), cyan (C), and black (K). In the following, when it is necessary to distinguish YMCK, description will be made by adding any of Y, M, C, and K after the reference. When YMCK does not need to be distinguished, Y, M, C, K is omitted.

  The image forming units 10Y, 10M, 10C, and 10K are arranged so that the image forming units 10Y, 10Y, 10Y, 10K, 10K, 10K They are arranged in series in the order of 10M, 10C, and 10K. In addition, the intermediate transfer belt 30 is provided with a primary transfer roll 16Y disposed opposite to the photosensitive drums 12Y, 12M, 12C, and 12K as image carriers of the image forming units 10Y, 10M, 10C, and 10K. It passes between 16M, 16C, and 16K.

  Next, the configuration of each of the image forming units 10Y, 10M, 10C, and 10K and the image forming operation will be described with respect to the image forming unit 10Y that forms a yellow toner image.

  The image forming unit 10Y is provided with a charging roll 22Y that uniformly charges the surface of the photosensitive drum 12Y so as to be in contact with the surface of the photosensitive drum 12Y. Further, an exposure device 14Y is provided on the surface of the uniformly charged photoconductive drum 12Y for performing image exposure corresponding to the yellow image and forming an electrostatic latent image corresponding to the yellow image on the surface.

  Further, a developing device 15Y provided with a developing roll 18Y that visualizes an electrostatic latent image corresponding to a yellow image as a yellow toner image with toner is provided, and further, by an electrostatic attraction force due to a transfer bias to which the yellow toner image is applied. A primary transfer roll 16Y that performs primary transfer on the intermediate transfer belt 30 is provided.

  Further, in this primary transfer, all of the yellow toner image is not transferred to the intermediate transfer belt 30, and a part thereof remains on the photosensitive drum 12Y as transfer residual yellow toner. Furthermore, toner external additives and the like are also attached to the surface of the photosensitive drum 12Y. Therefore, a photoconductor cleaner 20Y that removes transfer residual toner and the like on the surface of the photoconductor drum 12Y is provided in contact with the photoconductor drum 12Y, and the photoconductor drum 12Y after the primary transfer is connected to the photoconductor cleaner 20Y. After passing through the facing position, transfer residual toner and the like on the surface of the photosensitive drum 12Y are removed. Thereafter, the surface of the photosensitive drum 12Y is charged again by the charging roll 22Y for the next image forming cycle.

  In the image forming apparatus 100, an image forming process similar to the above is performed in each of the image forming units 10Y, 10M, 10C, and 10K at a timing that considers a relative position difference between the image forming units 10Y, 10M, 10C, and 10K. Then, the Y, M, C, and K color toner images are sequentially superimposed on the intermediate transfer belt 30 to form a multiple toner image.

  Then, the secondary transfer roll 36 that collectively transfers the multiple toner images formed on the intermediate transfer belt 30 onto the sheet member P that has been conveyed to the secondary transfer position A at a determined timing. Is provided. Further, a fixing device 40 is provided for fixing the multiple toner image formed on the sheet member P to the sheet member P by heat and pressure.

  The transfer device 38 that transfers the toner image formed on the intermediate transfer belt 30 to the sheet member P includes the secondary transfer roll 36 and the support roll 34 described above. Details will be described later.

(Main part configuration)
Next, the transfer device 38 will be described in detail.

  The transfer device 38 is provided with a support roll 34 made of EPDM while supporting the intermediate transfer belt 30 from the inside, and a negative voltage (-5000 V in the present embodiment) is applied to the support roll 34. Yes. Further, the support roll 34 and the intermediate transfer belt 30 are disposed so as to face each other, and the secondary transfer roll 36 formed of urethane is grounded and set to a reference potential point (0 V).

  As shown in FIG. 1, with this configuration, an electric field is generated from the secondary transfer roll 36 toward the support roll 34, and the negative toner on the intermediate transfer belt 30 repels the support roll 34 applied with a negative voltage. Then, it is transferred to the sheet member P.

  Furthermore, discharge is possible between the secondary transfer roll 36 and the support roll 34 on the downstream side in the sheet member conveyance direction and on the opposite side of the sheet member P conveyed to the support roll 34. A neutralizing member 42 made of a conductive material is provided at the position.

  The static elimination member 42 is connected to one end of a resistance member 46 having a resistance (100 MΩ in this embodiment) through a connection line 44, and the other end of the resistance member 46 is grounded. The resistance value of the resistance member 46 can be changed.

  Furthermore, as shown in FIG. 2, when the direction orthogonal to the conveying direction in which the sheet member P is conveyed is the width direction (arrow D direction in the figure), the length in the width direction of the support roll 34 is equal to or higher than the charge removal. The length in the width direction of each member is determined so that the length in the width direction of the member 42> the length in the width direction of the sheet member P.

  That is, even when the sheet member P to be conveyed is disposed between the support roll 34 and the charge removal member 42, the discharge occurs between the support roll 34 and the charge removal member 42 on the outer side in the width direction of the sheet member P. It has become.

  With this configuration, a discharge occurs between the support roll 34 and the secondary transfer roll 36, and a negative charge is charged on the surface of the charge removal member 42. The charge amount of the negative charge is adjusted by the resistance member 46 whose resistance value can be changed. Is set to a predetermined value.

  On the other hand, as shown in FIG. 1, on the upstream side of the secondary transfer roll 36 in the sheet member conveyance direction, a plate-shaped guide member 48 formed of a conductive member that guides the sheet member P to the secondary transfer position A is provided. Has been placed.

(Function)
Next, the operation of the transfer device 38 will be described.

  As shown in FIG. 3, the multiple toner images transferred onto the intermediate transfer belt 30 by the image forming units 10Y, 10M, 10C, and 10K are conveyed toward the secondary transfer position A by the intermediate transfer belt 30. The

  As shown in FIG. 1, an electric field is generated between the secondary transfer roll 36 and the support roll 34 disposed at the secondary transfer position A from the secondary transfer roll 36 toward the support roll 34. Then, the negative toner on the intermediate transfer belt 30 repels the support roll 34 applied with a negative voltage and is transferred to the sheet member P conveyed toward the secondary transfer position A. The sheet member P is charged to the plus side compared to the support roll 34 (in the present embodiment, it is charged to the plus).

  On the other hand, a discharge occurs between the support roll 34 and the charge removal member 42, and a negative charge is charged on the surface of the charge removal member 42, and the charge amount of the negative charge is adjusted by the resistance member 46 and becomes a predetermined value. .

  Therefore, since the sheet member P having its tip passed through the secondary transfer position A is positively charged as described above, it is likely to be attracted to the support roll 34 applied negatively.

  Here, as described above, a negative charge is charged on the surface of the static elimination member 42, the positively charged sheet member P is attracted, and the sheet member P is peeled off from the support roll 34.

  That is, by charging the surface of the charge removal member 42 with a negative charge, the potential gradient generated between the charge removal member 42 and the sheet member P is made larger than the potential gradient generated between the sheet member P and the support roll 34. . As a result, the sheet member P is pulled toward the charge removal member 42 and the sheet member P is peeled off from the support roll 34.

  In this way, by separating the sheet member P from the support roll 34, the sheet member P is conveyed to the fixing device 40 without being jammed.

  Next, a second embodiment of the transfer apparatus of the present invention will be described with reference to FIG. In addition, about the same member as 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As shown in FIG. 4, the static elimination member 52 of the transfer apparatus 50 of the present embodiment is not grounded via a resistance member. Instead, the static elimination member 52 is a diode as a rectifier that releases positive charges. 54 is grounded.

  That is, the negative charge is left on the surface of the static elimination member 52 and the positive charge generated on the surface of the static elimination member 52 is released.

  That is, by leaving a negative charge on the surface of the charge removal member 42, the potential gradient generated between the charge removal member 42 and the sheet member P is made larger than the potential gradient generated between the sheet member P and the support roll 34. As a result, the sheet member P is pulled toward the charge removal member 42 and the sheet member P is peeled off from the support roll 34.

  Next, a third embodiment of the transfer apparatus of the present invention will be described with reference to FIG. In addition, about the same member as 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As shown in FIG. 5, unlike the first embodiment, the charge removal member 62 of the transfer device 60 of the present embodiment is grounded through a resistance member 64 connected in parallel to a diode 66 as a rectifier that releases positive charges. Has been.

  That is, the diode 66 leaves the negative charge on the surface of the static elimination member 62 while releasing the positive charge generated on the surface of the static elimination member 62, and the resistance member 64 reduces the amount of negative charge charged on the surface of the static elimination member 62. adjust.

  That is, by leaving a negative charge on the surface of the charge removal member 42 and adjusting the amount of charge of the negative charge to a predetermined value, the potential gradient generated between the charge removal member 42 and the sheet member P is changed to the sheet member P. The potential gradient generated between the support roll 34 and the support roll 34 is made larger. As a result, the sheet member P is pulled toward the charge removal member 42 and the sheet member P is peeled off from the support roll 34.

  Next, a fourth embodiment of the transfer apparatus of the present invention will be described with reference to FIG. In addition, about the same member as 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As shown in FIG. 6, unlike the first embodiment, the connection line 44 and the guide member 48 that electrically connect the charge removal member 72 and the resistance member 74 of the transfer device 70 of the present embodiment are electrically connected to each other. 76 is connected.

  And the static elimination member 72 side of the resistance member 74 has a negative voltage due to a voltage drop. Therefore, when the sheet member P is a sheet member P having a low resistance value such as water-containing paper, when the leading end of the conveyed sheet member P reaches between the charge removal member 72 and the support roll 34, the charge removal member 72 is removed. It is conceivable that a current flows from the side through the sheet member P to the support roll 34 side (in the direction of arrow F in the figure) to disturb the toner image.

  However, as described above, the guide member 48 and the connection line 44 are electrically connected through the connection line 76. For this reason, when the leading end of the sheet member P guided by the guide member 48 is sandwiched between the support roll 34 and the secondary transfer roll 36, the current flows from the charge removal member 72 side of the resistance member 74 to the connection line 76, the guide member 48, and Since it flows through the sheet member P toward the support roll 34 (in the direction of arrow G in the figure), the aforementioned current flow in the F direction that disturbs the toner image is suppressed.

  Although the present invention has been described in detail with respect to specific embodiments, the present invention is not limited to such embodiments, and various other embodiments are possible within the scope of the present invention. It is clear to the contractor. For example, in the above-described embodiment, the toner image is transferred via the intermediate transfer belt 30. However, the toner image is directly transferred from the roll to the sheet member P without the intermediate transfer belt. May be.

1 is a configuration diagram illustrating a transfer device according to a first embodiment of the present invention. It is the top view which showed the static elimination member, the support roll, etc. which were employ | adopted for the transfer apparatus which concerns on 1st Embodiment of this invention. 1 is a schematic configuration diagram illustrating an image forming apparatus employing a transfer device according to a first embodiment of the present invention. It is the block diagram which showed the transfer apparatus which concerns on 2nd Embodiment of this invention. It is the block diagram which showed the transfer apparatus which concerns on 3rd Embodiment of this invention. It is the block diagram which showed the transfer apparatus which concerns on 4th Embodiment of this invention.

34 Support roll (conveying member)
36 Secondary transfer roll (transfer member)
38 Transfer device 42 Static elimination member 44 Connection line (connection member)
46 Resistance member 52 Static elimination member 54 Diode (rectifier)
62 Static elimination member 64 Resistance member 66 Diode (rectifier)
72 Static elimination member 74 Resistance member 76 Connection line (conductive member)
100 Image forming apparatus

Claims (7)

A conveying member that rotates and conveys the recording medium while a negative voltage is applied;
A transfer member provided opposite to the conveying member and sandwiching a conveyed recording medium with the conveying member to transfer a toner image to the recording medium;
Provided downstream of the transfer member in the recording medium conveyance direction, on the opposite side of the recording medium conveyed to the conveyance member, and disposed at a position where discharge can be performed between the transfer member and the conveyance member. And a static elimination member that is grounded through a resistance member;
A transfer device. A conveying member that rotates and conveys the recording medium while a negative voltage is applied;
A transfer member provided opposite to the conveying member and sandwiching a conveyed recording medium with the conveying member to transfer a toner image to the recording medium;
Provided downstream of the transfer member in the recording medium conveyance direction, on the opposite side of the recording medium conveyed to the conveyance member, and disposed at a position where discharge can be performed between the transfer member and the conveyance member. And a static elimination member that is grounded through a rectifier that releases positive charges,
A transfer device. A conveying member that rotates and conveys the recording medium while a negative voltage is applied;
A transfer member provided opposite to the conveying member and sandwiching a conveyed recording medium with the conveying member to transfer a toner image to the recording medium;
Provided downstream of the transfer member in the recording medium conveyance direction, on the opposite side of the recording medium conveyed to the conveyance member, and disposed at a position where discharge can be performed between the transfer member and the conveyance member. And a static elimination member that is grounded through a rectifier that releases positive charges and a resistance member that is connected in parallel to the rectifier,
A transfer device.   The transfer device according to claim 1, wherein the resistance member is a variable resistance member capable of changing a resistance value of the resistance member. A guide member that guides the recording medium to the holding portion of the transfer member and the transfer member;
A connection member for electrically connecting the resistance member and the charge removal member;
A conducting member for electrically connecting the guide member and the connecting member;
The transfer device according to claim 1, 3 or 4. When the direction perpendicular to the transport direction in which the recording medium is transported is the width direction,
The transfer apparatus according to claim 1, wherein the length in the width direction of the conveying member ≧ the length in the width direction of the static elimination member> the length in the width direction of the recording medium is satisfied. A transfer device according to any one of claims 1 to 6;
A fixing device for fixing the toner image transferred to the recording medium by the transfer device;
An image forming apparatus comprising:

Images