JP2008003449A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent transfer material from being soiled due to soiling at the tip of a transfer material guiding member by suspended toner separated and scattered from a toner image carried on an image carrier. <P>SOLUTION: The image forming apparatus has: the image carrier; an image forming part to form a toner image on the surface of the image carrier; a transfer means to transfer the toner image formed on the image carrier to the transfer material; and the transfer material guiding member arranged on the upstream side of the transfer means in a transfer material conveying direction and guiding the transfer material conveyed to the transfer part of the transfer means. The transfer material guiding member has a non-contact member arranged on the image carrier side in non-contact with the image carrying surface of the image carrier, and is provided with a conductive non-contact toner collection member on the surface of the non-contact member. The non-contact toner collection member is arranged so that potential to the image carrier can be higher than that at any spot of the non-contact member. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a copying machine, a printer, a facsimile machine, and an image forming apparatus using an electrophotographic system having these functions. In particular, a toner image carried on the surface of an image carrier such as a photoconductor is transferred by a transfer unit. The present invention relates to an image forming apparatus that contacts and transfers to a transfer material, and an image forming apparatus that superimposes and transfers a plurality of color toner images formed on an intermediate transfer body onto a transfer material.

  As an image forming apparatus that contacts and transfers a toner image carried on the surface of a toner image carrier or the like onto a transfer material by a transfer unit, those described in Patent Documents 1 and 2 are known.

  Patent Document 1 is an image forming apparatus in which a lower guide member that guides a transfer material to a transfer portion is composed of a conductive member and an insulating member, and a protruding portion is provided on the insulating member.

In Patent Document 2, a toner collection member is disposed at a contact start portion where an intermediate transfer belt carrying a toner image starts to come into contact with a support roller, and a separation start portion which starts separation and a position opposite to the intermediate transfer belt. An image forming apparatus provided.
JP 2002-139922 A JP 2003-280400 A

  The prior art of Patent Document 1 is an image forming apparatus that prevents toner from accumulating on the lower guide plate to prevent the transfer material from being soiled, and also prevents transfer omission of the moisture-absorbed transfer material. This is different from that for collecting floating toner generated near the toner image on the carrier.

  The conventional technique of Patent Document 2 suppresses toner scattering that occurs at a contact start portion that starts contact with an intermediate transfer belt support roller carrying a toner image and a separation start portion that starts separation. If it is not provided immediately before the transfer portion, transfer material contamination occurs, which is insufficient for toner scattering countermeasures. Further, the toner collecting member is not integrated with the transfer material guide member.

  Generally, a guide member that guides a transfer material is provided in the transfer portion. The tip of the guide member has the highest potential with respect to the image carrier. That is, since the front end portion of the guide member is closest to the image carrier, toner may accumulate on the front end portion of the guide member and stain the transfer material. In order to prevent this, a protrusion on the insulating member may be provided, but the insulating member does not actively collect the toner, and as a result, the toner stains concentrate on the tip of the guide member having the strongest potential. Deposited.

  The present invention has been made in view of the above-described technical background, and the object thereof is floating toner that scatters freely from a toner image carried on an image carrier such as a photosensitive drum or an intermediate transfer member. It is an object of the present invention to provide an image forming apparatus that prevents transfer material contamination caused by contamination of the tip of a transfer material guide member.

The object is achieved by the configurations described below.
An image carrier, an image forming unit that forms a toner image on the surface of the image carrier, a transfer unit that transfers the toner image formed on the image carrier to a transfer material, and a transfer material conveyance of the transfer unit A transfer material guide member that is disposed upstream in the direction and guides a transfer material conveyed to a transfer portion of the transfer unit, wherein the transfer material guide member is an image carrying surface of the image carrier. A non-contact member disposed on the image carrier side in a non-contact manner, and a conductive non-contact toner collecting member is provided on a surface of the non-contact member, and the non-contact toner collecting member is disposed on the non-contact member. An image forming apparatus, wherein the image forming apparatus is arranged such that the potential with the image carrier is stronger than any of the above.

  According to the image forming apparatus of the present invention, it is possible to prevent the transfer material stain caused by the contamination of the tip of the transfer material guide member due to the floating toner that is separated from the toner image carried on the image carrier.

  The present invention will be described below with reference to embodiments, but the present invention is not limited to the embodiments described below.

[Color image forming apparatus]
FIG. 1 is a cross-sectional view showing the overall configuration of a color image forming apparatus A according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing the main part of the color image forming apparatus A.

  The color image forming apparatus A is called a tandem type color image forming apparatus, and includes a plurality of sets of image forming units 10Y, 10M, 10C, and 10K, a belt-like intermediate transfer member (image carrier) 7, a primary transfer. An intermediate transfer unit comprising means 5Y, 5M, 5C, 5K and secondary transfer means 8, a fixing device 11, and a paper feeding device 20 are provided.

  Above the color image forming apparatus A, an image reading apparatus B is installed. The document placed on the document table is scanned and exposed by the optical system of the document image scanning exposure apparatus of the image reading apparatus B, and read by the line image sensor. The analog signal photoelectrically converted by the line image sensor is subjected to analog processing, A / D conversion, shading correction, image compression processing, etc. in the image processing unit, and then input to the exposure means 3Y, 3M, 3C, 3K. .

  The image forming unit 10Y that forms a yellow (Y) image includes a charging unit 2Y, an exposure unit 3Y, a developing unit 4Y, and a cleaning unit 6Y disposed around the image carrier 1Y.

  The image forming unit 10M that forms a magenta (M) color image includes an image carrier 1M, a charging unit 2M, an exposure unit 3M, a developing unit 4M, and a cleaning unit 6M.

  The image forming unit 10C that forms a cyan (C) image includes an image carrier 1C, a charging unit 2C, an exposure unit 3C, a developing unit 4C, and a cleaning unit 6C.

  The image forming unit 10K that forms a black (K) image includes an image carrier 1K, a charging unit 2K, an exposure unit 3K, a developing unit 4K, and a cleaning unit 6K.

  The charging unit 2Y and the exposure unit 3Y, the charging unit 2M and the exposure unit 3M, the charging unit 2C and the exposure unit 3C, and the charging unit 2K and the exposure unit 3K constitute a latent image forming unit.

  As the image bearing members 1Y, 1M, 1C, and 1K, known ones such as an OPC photosensitive member and an aSi photosensitive member are used. An OPC photosensitive member is preferable, and in particular, a negatively charged OPC photosensitive member is preferable. In the form, negatively chargeable OPC is used.

  As the charging means 2Y, 2M, 2C, 2K, a corona discharge means such as a scorotron or a corotron is used, and a scorotron discharge means is preferably used.

  As the exposure means 3Y, 3M, 3C, and 3K, light emitting elements that emit light according to image data, such as lasers and LED arrays, are used.

  The belt-like intermediate transfer member 7 is semiconductive and is wound around a plurality of support rollers 71, 72, 73, 74 and a backup roller 75, and is supported so as to be able to circulate. In the present embodiment, the intermediate transfer member 7 is supported between the support rollers 73 and 74 in a planar shape.

  The images of the respective colors formed by the image forming units 10Y, 10M, 10C, and 10K are sequentially transferred (primary transfer) and synthesized on the rotating intermediate transfer body 7 by the primary transfer means 5Y, 5M, 5C, and 5K. A color image is formed.

  The transfer material P accommodated in the paper feeding cassette 21 of the paper feeding device 20 is fed by a paper feeding means (first paper feeding unit) 22, and is fed with paper feeding rollers 23, 24, 25 and registration rollers (second feeding). The paper is conveyed to the secondary transfer means 8 through the paper portion 26 and the conveyance roller 27, and the color image is transferred onto the transfer material P (secondary transfer).

  The transfer material P onto which the color image has been transferred is subjected to heat and pressure by the fixing device 11, and the color or single color toner image t on the transfer material P is fixed and fixed on the transfer material P, and the paper discharge roller 28 and is placed on a paper discharge tray 29 outside the apparatus.

  On the other hand, after the color image is transferred to the transfer material P by the secondary transfer unit 8, the residual toner is removed by the cleaning unit 6A from the intermediate transfer body 7 from which the transfer material P is separated by curvature.

[Primary transfer means]
The primary transfer means 5Y for transferring a yellow image is composed of a primary transfer roller 5YA and a DC power source 5YE for applying a voltage to the primary transfer roller 5YA.

  The primary transfer means 5M for transferring a magenta color image includes a primary transfer roller 5MA and a DC power source 5ME for applying a voltage to the primary transfer roller 5MA.

  The primary transfer means 5C for transferring a cyan image is composed of a primary transfer roller 5CA and a DC power source 5CE for applying a voltage to the primary transfer roller 5CA.

  The primary transfer means 5K for transferring a black image is composed of a primary transfer roller 5KA and a DC power supply 5KE for applying a voltage to the primary transfer roller 5KA. The primary transfer roller 5KA is opposed to the image carrier 1K through the intermediate transfer member 7 and is in sliding contact with the inner surface of the intermediate transfer member 7.

  A current value of 40 μA and a voltage value of +1.5 kV are applied to the DC power supplies 5YE, 5ME, 5CE, and 5KE of the primary transfer units 5Y, 5M, 5C, and 5K.

  Further, the primary transfer rollers 5YA, 5MA, 5CA, and 5KA are moved by driving means (not shown) at times other than the primary transfer, and are moved away from the inner surface of the intermediate transfer body 7.

[Secondary transfer means]
The secondary transfer unit 8 includes a backup roller 75, a secondary transfer roller 8A, a DC power source 8E, and the like. The backup roller 75 made of a conductive material faces the secondary transfer roller 8 </ b> A through the intermediate transfer body 7 and is in sliding contact with the inner surface of the intermediate transfer body 7.

  The backup roller 75 is connected to a DC power source 8E that applies a DC voltage. A current value of 50 μA and a voltage value of +3 kV are applied to the DC power supply 8E of the secondary transfer unit 8. The DC power supply 8E transfers the residual toner attached to the secondary transfer roller 8A in contact with the intermediate transfer body 7 to the intermediate transfer body 7 by applying a reverse bias and cleans it.

  The backup roller 75 has substantially the same configuration as the primary transfer rollers 5YA, 5MA, 5CA, and 5KA, and is pressure-bonded to the inner surface side of the intermediate transfer body 7. The conductive backup roller 75 is formed by a roller body and an elastic layer formed on the surface of the roller body.

The intermediate transfer member 7 is a single layer or multilayer belt made of polyamide, polyimide, or the like, and has a volume resistivity of 10 ⁷ to 10 ¹² Ωcm.

  The intermediate transfer member 7 is secondarily transferred to the transfer material P by the secondary transfer unit 8 and then cleaned by passing through the cleaning unit 6A.

  The conductive secondary transfer roller 8A is formed of a roller body and an elastic layer formed on the surface of the roller body. The secondary transfer roller 8 </ b> A is moved by a driving unit (not shown) and retracted away from the surface of the intermediate transfer body 7 at times other than the secondary transfer.

  FIG. 3 is a cross-sectional view showing a non-contact toner collecting member disposed in the vicinity of the secondary transfer unit 8.

  The transfer material P that is nipped and conveyed by the conveyance roller 27 includes an upper guide plate (non-contact member, first guide plate) 31 that is close to the intermediate transfer body 7 and a lower guide plate that faces the upper guide plate 31 ( A secondary transfer nip portion (transfer portion) where the secondary transfer roller 8A and the backup roller 75 are in pressure contact with each other through a transfer material conveyance path formed between transfer material guide members formed of a second guide plate 32. ) Pass through N1.

  A conductive non-contact toner collecting member (hereinafter referred to as a toner collecting member) is provided on the upper surface side of the upper guide plate 31, that is, on the upper side of the surface where the upper guide plate 31 faces the toner image carrying surface of the intermediate transfer body 7. 33) is fixedly arranged. The toner collecting member is connected to a DC power source (voltage applying means) 34.

  The toner collection member 33 is disposed downstream of the transfer portion of the primary transfer roller 5KA, upstream of the transfer portion of the secondary transfer roller 8A, and excluding the tip position of the upper guide plate 31. Further, the toner collecting member 33 is provided in a direction orthogonal to the transfer direction of the transfer material P. The toner collecting member 33 is formed longer than the image forming width that can be formed on the image carrier.

  A gap g1 between the upper surface of the toner collecting member 33 and the toner image carrying surface of the intermediate transfer member 7 is set smaller than a gap g2 between the upper guide plate 31 and the toner image carrying surface of the intermediate transfer member 7 (a < b).

  Further, the toner collecting member 33 is disposed so that the potential with the intermediate transfer member 7 is stronger than any portion of the upper guide plate 31.

  The toner collecting member 33 is charged with a polarity opposite to that of the toner scattered from the intermediate transfer member 7 and electrostatically attracts and collects the toner scattered from the intermediate transfer member 7.

  The potential of the toner collecting member 33 is desirably kept as low as possible due to problems such as leakage. For example, the floating toner can be efficiently collected by setting the potential of the toner collecting member 33 to 2 kV or less.

  Further, since the toner is electrostatically collected by the toner collecting member 33, the floating toner can be efficiently collected even when a polymerized toner having a small particle diameter of 6 μm or less is used.

  The gap between the intermediate transfer member 7 and the toner collecting member 33 is preferably within a predetermined value range. When approaching a lower limit (for example, 2 mm) within a predetermined value range, when a bias voltage is applied to the toner collecting member 33, the bias voltage may adversely affect the image. On the other hand, when the gap exceeds the upper limit (for example, 10 mm), the toner may be scattered from the toner collecting member 33.

  The toner collecting member 33 fixed to the upper guide plate 31 is supported by the main body of the color image forming apparatus A in a replaceable manner. When the amount of toner collected by the toner collecting member 33 exceeds the limit, the toner collecting member 33 is replaced with the upper guide plate 31. As a result, when the amount of collected toner exceeds the limit, it is possible to prevent the toner from scattering from the toner collecting member 33 and to collect the floating toner efficiently at all times.

[Image forming apparatus]
FIG. 4 is a cross-sectional view showing the image forming unit 10 of the image forming apparatus.

  Around the image carrier 1, a charging unit 2, an exposure unit 3, a developing unit 4, a transfer unit 9, and a cleaning unit 6 are arranged in the order of the image forming process.

  The transfer unit 9 includes a transfer roller 9A, a DC power source 9E, and the like. The conductive transfer roller 9A is formed by a rotating shaft and an elastic layer formed on the surface of the rotating shaft. Both ends of the rotating shaft are rotatably supported by the bearing 9B.

  Conductive non-contact toner collection on the surface of the upper guide plate (non-contact member, first guide plate) 41 on the upstream side in the rotation direction of the image carrier 1 of the transfer nip portion (transfer portion) N2 of the transfer means 9. A member (hereinafter referred to as a toner collecting member) 43 was provided.

  The arrangement position of the toner collecting member 43 is arranged on the downstream side of the developing unit of the developing unit 4 and on the upstream side of the transfer unit of the transfer roller 9 </ b> A, and is a position excluding the tip position of the upper guide plate 41. Further, the toner collecting member 43 is provided in a direction orthogonal to the transfer direction of the transfer material P. The toner collecting member 43 (particularly its upper surface) is formed longer than the image forming width that can be formed on the image carrier 1. As a result, the gap between the upper surface of the toner collecting member 43 and the toner image carrying surface of the image carrier 1 is set smaller than the gap between the upper guide plate 41 and the toner image carrying surface of the image carrier 1.

  Further, the potential of the toner collecting member 43 and the image carrier 1 is stronger than that of any part of the upper guide plate 41.

  The transfer roller 9A and the image carrier 1 pass through a transfer material conveyance path formed between transfer material guide members composed of a lower guide plate (second guide plate) 42 facing the upper guide plate 41. It passes through a transfer nip portion (transfer portion) N2 that is in pressure contact.

  Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In this embodiment, an image is formed by the color image forming apparatus A provided with the primary transfer means 5Y, 5M, 5C and 5K and the secondary transfer means 8 shown in FIG.

[Image formation conditions]
Image forming apparatus: Tandem type full color copier (Konica Minolta 8050 (registered trademark) modified machine, see FIG. 1), continuous copying speed: full color mode, output 51 sheets per minute with A4 size transfer material Image carrier 1Y, 1M, 1C , 1K: outer diameter φ 60 mm, organic optical semiconductor, photosensitive layer thickness 25 μm, total exposure potential −50V to 0V
Transfer line speed of transfer material P: 220 mm / sec
Developer: Carrier average particle size 20-60 μm, polymerization toner average particle size 3-7 μm
Charging means 2Y, 2M, 2C, 2K: charging voltage V0 is -700V (variable: standard values on the left)
Exposure means 3Y, 3M, 3C, 3K: semiconductor laser (wavelength 780 nm), surface potential Vi of the image forming body at the time of exposure is −50 V, and power of the semiconductor laser is 300 μW
Developing means 4Y, 4M, 4C, 4K: The developing sleeve potential Vdc is -500 V, the developing bias voltage AC component Vac is a rectangular wave (frequency 5 kHz) of 1 kVp-p,
Primary transfer rollers 5YA, 5MA, 5CA, 5KA: using conductive roller, roller pressing 50N (Newton), transfer current 40μA, transfer voltage + 1.5kV applied, outer diameter φ20mm
Primary transfer means: A foaming roller (outer diameter 20 mm) is installed on the back of the intermediate transfer member, and a predetermined current value is selected and applied from a current value obtained by assembling a matrix with a greenhouse temperature and a counter.

Secondary transfer means 8: The electrical resistance values of the backup roller 75 and the secondary transfer roller 8A are both 4 × 10 ⁷ Ω, and a predetermined current value is selected and applied from a current value table in which a matrix is formed of temperature and humidity and a counter. To do.

Pressing force F: 50 N (Newton), transfer material conveyance direction nip width: 3 mm,
Elastic layer of secondary transfer roller 8A: semiconductive NBR solid rubber (acrylonitrile butadiene rubber), surface coating of elastic layer, volume resistance 4 × 10 ⁷ Ω, outer diameter φ30 mm, rubber hardness 67 ° ± 3 °,
Axial length of the elastic layer of the secondary transfer roller 8A: LA = 150 mm, LB = 250 mm, LC = 330 mm,
Backup roller 75: electric resistance value 4 × 10 ⁷ Ω, volume resistance value 4 × 10 ⁷ Ω, outer diameter φ30 mm, rubber hardness 67 ° ± 3 °, surface coating of elastic layer,
Intermediate transfer member 7: seamless semiconductive resin belt, volume resistivity 10 ¹¹ Ωcm, volume resistivity 10 ⁸ , polyimide resin, tension tension 50N, linear velocity 220 mm / sec,
Toner collecting member 33: metal member, application of bias voltage, potential of 2 KV or less,
[Comparative Example 1]
FIG. 5 is a cross-sectional view showing a comparative example of the secondary transfer means 8.

  FIG. 5A is a cross-sectional view of the secondary transfer unit 8 having a configuration in which the toner collecting member 33 is not provided on the upper guide plate 31 shown in FIG. In addition, about the code | symbol used in the figure, the same code | symbol as the thing of the said Example is attached | subjected to the part which has the same function as FIG. Further, differences from the above embodiment will be described.

In the secondary transfer means 8 having this configuration, the transfer material P is smeared as a result of printing 10,000 sheets of secondary color solid image (toner adhesion amount of the intermediate transfer member: 9 g / m ² ) on the A4 size transfer material P. did.

[Comparative Example 2]
FIG. 5B shows a secondary transfer having a configuration in which the toner collecting member 33 is not provided on the upper guide plate 31 shown in FIG. 3 and is arranged along the curvature of the intermediate transfer body 7 around which the support roller 74 is wound. FIG.

Also in the secondary transfer means 8 having this configuration, as a result of printing 10000 sheets of secondary color solid images (toner adhesion amount of the intermediate transfer member: 9 g / m ² ) on the A4 size transfer material P, smearing of the transfer material occurs. did.

FIG. 6 is a characteristic diagram showing the toner accumulation amount (g / m ² ) on the intermediate transfer member 7.

  In the figure, a curve a shows an embodiment (see FIG. 3) having the toner collecting member 33 on the upper guide plate 31. The toner collecting effect that a large amount of toner adheres to the vicinity of the upper surface of the toner collecting member 33 is great, and transfer material contamination due to toner scattering from the toner image on the intermediate transfer member 7 is suppressed.

  A curve b is a toner accumulation characteristic of the secondary transfer unit 8 (see FIG. 5A) shown in the first comparative example. The floating toner accumulates on the front end portion of the upper guide plate 31, and the transfer material P being conveyed comes into contact with the upper guide plate 31 to cause toner contamination.

  A curve c is a toner accumulation characteristic of the secondary transfer unit 8 (see FIG. 5B) shown in the comparative example 2. By arranging the toner collecting member 35 along the curvature of the intermediate transfer body 7 that winds the support roller 74, the floating toner is reduced, but at the front end portion of the upper guide plate 31 close to the intermediate transfer body 7. The floating toner accumulates, and the transfer material P being conveyed comes into contact with the upper guide plate 31 to cause toner contamination.

1 is a cross-sectional view illustrating an overall configuration of a color image forming apparatus according to an embodiment of the present invention. FIG. 3 is a cross-sectional view illustrating a main part of the color image forming apparatus. FIG. 3 is a cross-sectional view showing a non-contact toner collecting member disposed in the vicinity of a secondary transfer unit. FIG. 3 is a cross-sectional view illustrating an image forming unit of the image forming apparatus. Sectional drawing which shows the comparative example of a secondary transfer means. Characteristic chart showing toner accumulation amount on intermediate transfer member

Explanation of symbols

1,1Y, 1M, 1C, 1K Image carrier 4,4Y, 4M, 4C, 4K Developing means 5Y, 5M, 5C, 5K Primary transfer means 5YA, 5MA, 5CA, 5KA Primary transfer roller 7 Intermediate transfer body (image carrier) body)
71, 72, 73, 74 Support roller 75 Backup roller 8 Secondary transfer means 8A Secondary transfer roller 9 Transfer means 9A Transfer roller 9E DC power supply 31 Upper guide plate (non-contact member, first guide plate)
32 Lower guide plate (second guide plate)
33 Non-contact toner collecting member (toner collecting member)
34 DC power supply (voltage application means)
41 Upper guide plate (non-contact member)
42 Lower guide plate 43 Non-contact toner collecting member (toner collecting member)
N1 Secondary transfer nip (transfer)
N2 transfer nip (transfer)
A Color image forming device N1 Secondary transfer nip (transfer)
N2 transfer nip (transfer)
P transfer material

Claims (10)

An image carrier, an image forming unit that forms a toner image on the surface of the image carrier, a transfer unit that transfers the toner image formed on the image carrier to a transfer material, and a transfer material conveyance of the transfer unit An image forming apparatus having a transfer material guide member that is disposed upstream in the direction and guides a transfer material conveyed to the transfer unit of the transfer unit;
The transfer material guide member has a non-contact member disposed on the image carrier side in a non-contact manner on the image carrier surface of the image carrier,
A conductive non-contact toner collecting member is provided on the surface of the non-contact member,
An image forming apparatus, wherein the non-contact toner collecting member is arranged such that a potential with the image carrier is stronger than any portion of the non-contact member. The image carrier is an intermediate transfer member, and a toner image formed by a plurality of sets of image forming units is primarily transferred onto the surface of the intermediate transfer member by a primary transfer unit, and a plurality of images are formed on the surface of the intermediate transfer member. The image forming apparatus according to claim 1, wherein the toner images are superposed and a plurality of toner images are collectively transferred to a transfer material by a secondary transfer unit. The image forming apparatus according to claim 1, wherein the non-contact toner collecting member is provided in parallel to a direction orthogonal to a transfer direction of the transfer material. 4. The image forming apparatus according to claim 1, wherein the non-contact toner collecting member is formed longer than an image forming width that can be formed on the image carrier. 5. 5. The image forming apparatus according to claim 1, further comprising a voltage applying unit configured to apply a voltage to the non-contact toner collecting member and the transfer material guide member. The transfer material guide member includes a first guide plate above the transfer material conveyance path and a second guide plate below, and the non-contact toner collecting member is integrated with the first guide plate. The image forming apparatus according to claim 1, wherein the image forming apparatus is formed. 7. The method according to claim 1, wherein a distance between the non-contact toner collecting member and the image carrier is smaller than a distance between the transfer material guide member and the image carrier. The image forming apparatus described. The image forming apparatus according to claim 1, wherein an arrangement position of the non-contact toner collecting member is a position excluding a front end position of the transfer material guide member. The image forming apparatus according to claim 1, wherein the arrangement position of the non-contact toner collecting member is downstream of the developing unit of the image forming unit and upstream of the transfer unit of the transfer unit. 3. The image formation according to claim 2, wherein the non-contact toner collecting member is disposed downstream of the transfer portion of the primary transfer unit and upstream of the transfer unit of the secondary transfer unit. apparatus.

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