JP4048733B2 - Transfer device - Google Patents

Description

[0001]
[Technical field to which the invention belongs]
The present invention relates to adjustment of an image inclination in a transfer portion of an image forming apparatus using an intermediate transfer member, and more particularly to a secondary transfer portion adjusting means.
[0002]
[Prior art]
Conventionally, in an image forming apparatus using the above intermediate transfer member, a single color or a plurality of toner images of different colors are sequentially formed on a single or a plurality of image carriers, and a single color or A plurality of toner images of different colors are primary-transferred sequentially onto a belt-like intermediate transfer member, and then a plurality of toner images with different colors transferred onto the belt-like intermediate transfer member are recorded. It is configured to form a black and white or color image by performing secondary transfer on the medium at once and performing a fixing process.
[0003]
At that time, in the image forming apparatus using the intermediate transfer member, when a plurality of toner images having different colors transferred onto the belt-like intermediate transfer member are secondarily transferred onto the recording medium at once. In addition, the intermediate transfer member is supported by a backup roll from the inside, and the secondary transfer roll is brought into contact with the surface side of the intermediate transfer member, and a backup roll type transfer device that supplies voltage to the backup roll is adopted. ing.
[0004]
In such a backup roll type transfer apparatus, one end position of the backup roll is configured to be adjustable, and one end position of the backup roll is adjusted to change the alignment of the intermediate transfer member. The inclination of the image in the next transfer portion is adjusted. For example, Japanese Patent Application Laid-Open No. 2000-75680 discloses a technique that makes it possible to adjust the inclination of the image in the secondary transfer portion.
[0005]
[Problems to be solved by the invention]
However, the above prior art has the following problems. That is, in the case of the technique disclosed in the above Japanese Patent Application Laid-Open No. 2000-75680, one end position of the backup roll is configured to be adjustable, and one end position of the backup roll is adjusted, By changing the alignment of the transfer body, the inclination of the image in the secondary transfer portion is adjusted. For this reason, the position of the recording medium entering the secondary transfer position is regulated to an appropriate position by the registration roll that conveys the recording medium to the secondary transfer position, whereas the belt supported by the backup roll. Since the nip between the intermediate transfer member and the secondary transfer roll can only be adjusted to one end position of the backup roll, the type of recording medium differs even if the alignment of the intermediate transfer member can be adjusted. In this case, the nip state between the backup roll and the secondary transfer roll changes, and the recording medium having the higher nip pressure is conveyed in advance, and the image that is secondarily transferred to the recording medium is inclined. It had the problem that it ended up.
[0006]
Accordingly, the present invention has been made to solve the above-described problems of the prior art, and an object of the present invention is to adjust the inclination of an image at a transfer portion in an image forming apparatus using an intermediate transfer member. The present invention provides a transfer device that can compensate for a portion that cannot be adjusted in the past and increase the adjustment range, and can always adjust the inclination of an image even when the type of recording medium is different. .
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the invention described in claim 1 is directed to a back support member disposed on the back side of the intermediate transfer member, and a back support member disposed on the back side of the intermediate transfer member. In a transfer apparatus for transferring onto a recording medium conveyed to a transfer portion between a back side support member and a transfer member by a transfer electric field formed between the transfer member and the transfer member that is pressed against the surface of the intermediate transfer member.
A pressure contact width adjusting means for adjusting a pressure contact width (biting amount) of the transfer member with respect to the back support member ;
The pressure contact width adjusting means moves the transfer member in a direction in which the transfer member comes in contact with and separates from the back surface support member, and moves both end portions of the transfer member individually in a direction in which the transfer member comes into contact with and separates from the back surface support member. And the back support member is moved in a direction in which the back support member is brought into contact with and separated from the transfer member, and both ends of the back support member are individually moved in a direction in which the back support member is brought into contact with and separated from the transfer member. The transfer device is characterized in that the press contact width of the member with respect to the back support member is adjusted . Here, for example, a belt-like intermediate transfer member is used as the intermediate transfer member.
[0009]
Further, in the invention described in claim 2 , the press contact width adjusting means adjusts the press contact width of the transfer member with respect to the back support member according to the type and / or environment of the recording medium conveyed to the transfer unit. 3. The transfer device according to claim 1, wherein the transfer device is a transfer device. Here, the type of recording medium refers to the basis weight and size of the paper, and the environment refers to temperature and humidity. Note that the pressure contact width of the transfer member with respect to the back surface support member adjusted by the pressure contact width adjusting means may be configured so that the user can set an arbitrary value from the control panel or the like regardless of the type and environment of the recording medium.
[0010]
[Action]
In the present invention, since the press contact width adjusting means for adjusting the press contact width of the transfer member with respect to the back support member is provided, the press contact width at which the transfer member presses the back support member is adjusted by the press contact width adjusting means. As a result, the adjustment range of the tilt of the image at the transfer portion is greatly expanded, and the image can be transferred in a stable state at all times.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0012]
Embodiment 1
FIG. 2 is a schematic configuration diagram showing a tandem type color electrophotographic copying machine as an image forming apparatus according to Embodiment 1 of the present invention. Although this tandem type color electrophotographic copying machine is provided with an image reading device, the image forming device is not provided with an image reading device, and is based on image data output from a personal computer (not shown). Of course, a color printer, a facsimile, or the like that forms an image may be used.
[0013]
In FIG. 2, reference numeral 1 denotes a main body of a tandem type color electrophotographic copying machine. The color electrophotographic copying machine main body 1 has an image reading device (IIT) for reading an image of a document 2 at an upper portion on one end side thereof. : Image Input Terminal) 4, and inside the color electrophotographic copying machine main body 1, image data output from the image reading device 4, a personal computer (not shown) or the like, or a telephone line or a LAN The image processing apparatus (IPS: Image Processing System) 12 that performs predetermined image processing on the image data that is sent and the image output based on the image data that has been subjected to predetermined image processing by the image processing apparatus 12 An image output device (IOT: Image Output Terminal) 100 is provided. It has been.
[0014]
In the image reading device 4, an image of the original 2 pressed on the platen glass 5 by the platen cover 3 or an original conveyed automatically by an ADF (not shown) is read. The image reading device 4 illuminates a document 2 placed on a platen glass 5 with a light source 6, and reflects a reflected light image from the document 2 from a full-rate mirror 7, half-rate mirrors 8 and 9, and an imaging lens 10. The image reading element 11 composed of a CCD or the like is scanned and exposed through a reduction optical system, and the color material reflected light image of the document 2 is formed at a predetermined dot density (for example, 16 dots / mm) by the image reading element 11. It is configured to read.
[0015]
The color material reflected light image of the document 2 read by the image reading device 4 is subjected to image processing as, for example, document reflectance data of three colors of red (R), green (G), and blue (B) (8 bits each). The image processing apparatus 12 performs, for example, shading correction, position shift correction, brightness / color space conversion, gamma correction, frame deletion, color / moving editing, etc., on the reflectance data of the document 2. Predetermined image processing is performed.
[0016]
The image data that has been subjected to the predetermined image processing by the image processing apparatus 12 as described above is a four-color document of yellow (Y), magenta (M), cyan (C), and black (K) (each 8 bits). Converted to color material gradation data (raster data), as will be described below, yellow (Y), magenta (M), cyan (C), and black (K) image forming units 13Y, 13M, 13C, 13K laser writing devices 14Y, 14M, 14C, and 14K are sent to the laser writing devices 14Y, 14M, 14C, and 14K. In these laser writing devices 14Y, 14M, 14C, and 14K, image exposure using laser light LB is performed according to the original color material gradation data of a predetermined color Is done.
[0017]
By the way, inside the tandem type color electrophotographic copying machine main body 1, as described above, four image forming units 13Y of yellow (Y), magenta (M), cyan (C), and black (K), 13M, 13C, and 13K are arranged in parallel at regular intervals in the horizontal direction.
[0018]
These four image forming units 13Y, 13M, 13C, and 13K are all configured in the same manner, and roughly divided, a photosensitive drum 15 as an image carrier that is rotationally driven at a predetermined speed along the arrow A direction. And a scorotron 16 for primary charging as a charging means for uniformly charging the surface of the photosensitive drum 15 and a laser beam corresponding to the image information of each color on the surface of the photosensitive drum 15 for scanning exposure. The image forming apparatus (image forming means) includes a laser writing device 14 that forms an electrostatic latent image, a developing device 17 that develops an electrostatic latent image formed on the photosensitive drum 15, a cleaning device 18, and the like. Yes.
[0019]
As shown in FIG. 2, the laser writing device 14 modulates the semiconductor laser 19 according to the original color material gradation data, and emits a laser beam LB from the semiconductor laser 19 according to the gradation data. The laser beam LB emitted from the semiconductor laser 19 is deflected and scanned by the rotary polygon mirror 22 via the reflection mirrors 20 and 21, and again carries an image via the reflection mirrors 20 and 21 and the plurality of reflection mirrors 23 and 24. Scanning exposure is performed on the photosensitive drum 15 as a body.
[0020]
From the image processing device 12, the laser writing devices 14Y, 14M, 14C of the image forming units 13Y, 13M, 13C, and 13K of the respective colors of yellow (Y), magenta (M), cyan (C), and black (K) are provided. The image data (raster data) of each color is sequentially output to 14K, and laser beams LB emitted according to the image data from these laser writing devices 14Y, 14M, 14C, 14K are respectively photosensitive drums 15Y, 15M, The surfaces of 15C and 15K are scanned and exposed to form an electrostatic latent image. The electrostatic latent images formed on the photosensitive drums 15Y, 15M, 15C, and 15K are respectively yellow (Y), magenta (M), and cyan (C) by the corresponding developing devices 17Y, 17M, 17C, and 17K. , And developed as a toner image of each color of black (K).
[0021]
Yellow (Y), magenta (M), cyan (C), and black (K) sequentially formed on the photosensitive drums 15Y, 15M, 15C, and 15K of the image forming units 13Y, 13M, 13C, and 13K. The unfixed toner images of the respective colors are superimposed on the surface of the intermediate transfer belt 25 at a primary transfer position where the photosensitive drums 15Y, 15M, 15C, and 15K are in contact with the intermediate transfer belt 25 as an intermediate transfer member. Sequentially transferred. Semiconductive bias rolls 26Y, 26M, 26C, and 26K as transfer members are disposed on the back side of the intermediate transfer belt 25 at the primary transfer position. These bias rolls 26Y, 26M, 26C, and 26K are disposed. Thus, the intermediate transfer belt 25 comes into contact with the surfaces of the photosensitive drums 15Y, 15M, 15C, and 15K. The primary transfer bias rolls 26Y, 26M, 26C, and 26K are applied with a voltage having a polarity opposite to the charging polarity of the toner, and the respective colors formed on the photosensitive drums 15Y, 15M, 15C, and 15K are undetermined. The contact toner images are sequentially electrostatically attracted onto the intermediate transfer belt 25 to form a full-color image.
[0022]
The intermediate transfer belt 25 includes a drive roll 27, a driven roll 28, a tension roll 29, a driven roll 30, a secondary transfer opposing roll (hereinafter referred to as “backup roll”) 31, and an idle roll. 32 is stretched with a constant tension, and is circulated and driven at a predetermined speed in the direction of arrow B by a drive roll 27 that is rotationally driven by a dedicated drive motor that is excellent in constant speed (not shown). It is like that.
[0023]
When a single color image is formed, only the desired color image forming units 13Y, 13M, 13C, and 13K are operated, and a desired single color unfixed toner image is formed on the intermediate transfer belt.
[0024]
In this way, the unfixed toner images of the respective colors of yellow (Y), magenta (M), cyan (C), and black (K) that have been primary-transferred multiple times on the intermediate transfer belt 25 are intermediate transfer belt 25. Is rotated to the secondary transfer position facing the conveyance path of the recording paper 34 (recording medium), and an unfixed toner image is transferred from the intermediate transfer belt 25 to the recording paper 34 at the secondary transfer position. Next transferred. The recording paper 34 is fed from one of the print paper trays 39, 40, 41 by a feed roller 42, conveyed to a registration roller 47 by a paper conveyance path 46 having a plurality of conveyance rollers 43, 44, and temporarily stopped. The Next, the recording paper 34 is conveyed at a predetermined timing by registration rollers 47 and is sandwiched between the secondary transfer bias roll 33 for secondary transfer and the intermediate transfer belt 25. Further, on the back side of the intermediate transfer belt 25 at the secondary transfer position, a backup roll 31 that is opposed to the secondary transfer bias roll 33 and a metal roll (not shown) that contacts the backup roll 31 are disposed. . At the secondary transfer position, by applying a voltage (normal transfer bias) having the same polarity as the toner charging polarity to the metal roll, the secondary transfer bias roll 33 forms a transfer electric field as a counter electrode, The unfixed toner image carried on the transfer belt 25 is electrostatically transferred to the recording paper 34 at the secondary transfer position. The secondary transfer bias roll 33 for secondary transfer is cleaned by a brush roll (not shown).
[0025]
Then, the recording paper 34 onto which the unfixed toner image has been transferred is peeled off from the intermediate transfer belt 25, and then sent to the fixing device 37 by the paper transport belts 35 and 36 as the two transfer material transport means, and is unfixed. The toner image is fixed and discharged onto a discharge tray 38 provided outside the apparatus main body 1. The paper transport belts 35 and 36 are composed of an endless rubber belt 35c stretched between a driving roller 35a and a driven roller 35b, and five rubber belts are stretched in parallel by one paper transport belt. ing.
[0026]
As shown in FIG. 2, the intermediate transfer belt 25 after the secondary transfer of the unfixed toner image has its residual toner removed by a belt cleaner 48 located downstream of the secondary transfer portion. .
[0027]
By the way, in the first embodiment, the toner image transferred onto the intermediate transfer member is subjected to the back support member disposed on the back side of the intermediate transfer member and the surface of the intermediate transfer member facing the back support member. In a transfer apparatus for transferring onto a recording medium conveyed to a transfer portion between the back side support member and the transfer member by a transfer electric field formed between the transfer member and the transfer member that is pressed against the transfer member, the transfer member is pressed against the back support member. A pressure contact width adjusting means for adjusting the width (biting amount) is provided.
[0028]
In this embodiment, the press contact width adjusting means is configured to adjust the positions of both the transfer member and the back support member.
[0029]
Furthermore, in this embodiment, the press contact width adjusting means is configured to adjust the press contact width of the transfer member with respect to the back support member in accordance with the type of the recording medium conveyed to the transfer unit.
[0030]
FIG. 3 is a schematic configuration diagram of the secondary transfer bias roll and the backup roll of the transfer apparatus according to the first embodiment of the present invention.
[0031]
As shown in FIG. 3, the secondary transfer bias roll 33 is rotatably attached to the secondary transfer bias roll unit 50, and the backup roll is rotatably attached to the backup roll unit 51. The secondary transfer bias roll unit 50 and the backup roll unit 51 are provided on the secondary transfer bias roll 50 so as to engage with the positioning pin 52 provided on the backup roll unit 51 and the positioning pin 52. The recess 53 is relatively positioned.
[0032]
As shown in FIGS. 1 and 4, both ends of the secondary transfer bias roll are rotatably attached to the swing arm 54. The swing arm 54 is attached to the secondary transfer bias roll unit 50 so as to be swingable about a fulcrum 55. Further, first eccentric cams 56, 57 are disposed below the distal end portion 54 a of each swing arm 54, and the first eccentric cams 56, 57 are fixed to the rotary shaft 58. The rotating shaft 58 is rotationally driven by a driving gear 59 provided at one end thereof. An encoder 60 for detecting the reference position and the rotation amount of the first eccentric cams 56 and 57 is attached to the rotary shaft 58. Each swing arm 54 is urged by a coil spring 61 so that the tip 54 a is in pressure contact with the first eccentric cams 56 and 57. The secondary transfer bias roll 33 rotates the first eccentric cams 56 and 57 to change the angle of the swing arm 54 that is in pressure contact with the first eccentric cams 56 and 57. The nip width (pressure contact amount) with respect to the backup roll 31 can be adjusted.
[0033]
At that time, the first eccentric cams 56 and 57 are each divided into three regions along the circumferential direction thereof. That is, the first eccentric cams 56 and 57 have a region in which the secondary transfer bias roll 33 is moved in parallel in a direction in which the secondary transfer bias roll 33 is brought into contact with and separated from the backup roll 31, as shown in FIG. As shown in FIG. 5B, a region where only one end 33a of the secondary transfer bias roll 33 is moved in the direction of contacting and separating from the backup roll 31, and the secondary transfer bias roll 33 as shown in FIG. Only the other end 33b is configured to be provided with a region for moving in the direction of moving toward and away from the backup roll 31. The first eccentric cams 56 and 57 are not necessarily provided with these three regions, and may include one or two of the three regions.
[0034]
On the other hand, as described above, the backup roll 31 is rotatably attached to the backup roll unit 51, and the backup roll unit 51 is mounted on the front side as shown in FIGS. A frame 62 and a rear frame 63 are provided. Second eccentric cams 64 and 65 are respectively disposed on the front and rear frames 62 and 63, and the second eccentric cams 64 and 65 are fixed to the rotary shaft 66. It is attached with. The rotating shaft 66 is rotationally driven by a driving motor 69 having a driving gear 68 that meshes with the gear 67 via a gear 67 attached to the rotating shaft 66. Note that an encoder 70 for detecting the reference position and the rotation amount of the second eccentric cams 64 and 65 is attached to the rotary shaft 66. Further, the front and rear frames 62 and 63 are urged upward by a coil spring 71 attached to the upper end portion thereof, and the second eccentric cams 64 and 65 are as shown in FIG. Further, it is pressed against a roll 72 rotatably attached to the upper outer surface of the front side and rear side frames 62 and 63. The backup roller unit 51 including the front and rear frames 62 and 63 can be moved by rotating the second eccentric cams 64 and 65 by the drive motor 69.
[0035]
At this time, the second eccentric cams 64 and 65 are each divided into three regions along the circumferential direction thereof, and as described above, the backup roll provided with the front side and rear side frames 62 and 63. By moving the unit 51, as a result, the backup roll 31 rotatably attached to the backup roll unit 51 can be moved. That is, as shown in FIG. 9A, the second eccentric cams 64 and 65 are configured to move the backup roll 31 in a direction parallel to and away from the secondary transfer bias roll 33. As shown in FIG. 9B, an area in which only one end 31a of the backup roll 31 is moved in a direction in contact with and away from the secondary transfer bias roll 33, and the other end of the backup roll 31 as shown in FIG. An area for moving only 31 b in a direction to come in contact with and away from the secondary transfer bias roll 33 is provided. The second eccentric cams 64 and 65 do not necessarily include these three regions, and may include one or two of the three regions.
[0036]
Further, as shown in FIG. 1, the secondary transfer bias roll 33, the positioning pin 52, the backup roll 31, and the rotary shaft 66 of the second eccentric cams 64 and 65 are centered at a substantially straight line L. The direction in which the secondary transfer bias roll 33 and the backup roll 31 move and the direction in which the secondary transfer bias roll unit 50 and the backup roll unit 51 move are positioned on substantially one straight line. Is configured to do.
[0037]
In the above configuration, in the image forming apparatus provided with the transfer device according to this embodiment, when adjusting the inclination of the image at the transfer portion in the image forming device using the intermediate transfer member as follows, A portion that cannot be adjusted conventionally can be compensated for, and the adjustment range can be increased. Even when the type of recording medium is different, it is possible to always adjust the inclination of the image.
[0038]
That is, in the image forming apparatus provided with the transfer device according to this embodiment, both ends of both the secondary transfer bias roll 33 and the backup roll 31 can be adjusted as shown in FIGS. Thus, the nip width (biting amount) of the secondary transfer bias roll 33 can be changed, so that the adjustment range of the inclination of the image at the secondary transfer portion is greatly widened and can be easily adjusted.
[0039]
Further, the secondary transfer roll unit 50 and the backup roll unit 51 are configured so that the nominal reference position can be understood. Here, the eccentric cams 56, 57 and 64, 65 are used, so that the unit can be easily replaced. It is possible to return to the nominal state (reference position).
[0040]
【The invention's effect】
As described above, according to the present invention, in the image forming apparatus using the intermediate transfer member, when adjusting the inclination of the image at the transfer portion, the portion that cannot be adjusted conventionally is compensated and the adjustment range is increased. Therefore, it is possible to provide a transfer device that can always adjust the inclination of an image even when the types of recording media are different.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a transfer apparatus according to Embodiment 1 of the present invention.
FIG. 2 is a block diagram showing an image forming apparatus to which a transfer apparatus according to Embodiment 1 of the present invention is applied.
FIG. 3 is a front structural view of a main part showing a transfer apparatus according to Embodiment 1 of the present invention.
FIG. 4 is a front structural view of the main part showing the transfer apparatus according to Embodiment 1 of the present invention.
FIG. 5 is an explanatory view showing the operation of the transfer apparatus according to the first embodiment of the present invention.
FIG. 6 is a perspective view showing a main part of the transfer apparatus according to Embodiment 1 of the present invention.
FIG. 7 is a perspective view showing a main part of the transfer apparatus according to Embodiment 1 of the present invention.
FIG. 8 is a front view showing a main part of the transfer apparatus according to the first embodiment of the present invention.
FIG. 9 is an explanatory view showing the operation of the transfer apparatus according to the first embodiment of the present invention.
[Explanation of symbols]
31: Backup roll, 33: Secondary transfer bias roll, 50: Secondary transfer bias roll unit, 51: Backup roll unit, 52: Positioning pin, 53: Recess, 54: Swing arm, 56, 57: First Eccentric cams (pressure contact width adjusting means), 62, 63: front and rear frames, 64, 65: second eccentric cams.

Claims (3)

The toner image transferred onto the intermediate transfer member is placed between the back support member disposed on the back side of the intermediate transfer member and the transfer member that is pressed against the surface of the intermediate transfer member so as to face the back support member. In a transfer device for transferring onto a recording medium conveyed to a transfer portion between a back side support member and a transfer member by a transfer electric field formed,
A pressure contact width adjusting means for adjusting a pressure contact width of the transfer member with respect to the back support member ;
The pressure contact width adjusting means moves the transfer member in a direction in which the transfer member comes in contact with and separates from the back surface support member, and moves both ends of the transfer member in a direction in which the transfer member comes into contact with and separates from the back surface support member individually. And the back support member is moved in a direction in which the back support member is brought into contact with and separated from the transfer member, and both ends of the back support member are individually moved in a direction in which the back support member is brought into contact with and separated from the transfer member. A transfer device that adjusts a pressure contact width of a member to a back support member . The transfer apparatus according to claim 1, wherein the pressure contact width adjusting unit adjusts positions of one end and / or both ends of the transfer member and / or the back support member. The pressure contact width adjusting means adjusts the pressure contact width of the transfer member with respect to the back support member according to the type and / or environment of the recording medium conveyed to the transfer unit. Transfer device.

Images