JP2005099320A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance the heat efficiency of fixing processing and also to obtain a high-quality image by accurately selectively heating only the area of a toner image transferred to recording paper. <P>SOLUTION: The recording paper 5 electrified by a charge roller 17 is transported in tight-contact with a transfer belt 31 by a transport part 3, the toner image formed on a photoreceptor 11 is transferred to the recording paper 5 by the action of a transfer roller 14, and only the area of the toner image on the recording paper 5 is accurately selectively heated at a selective heating position D by starting the irradiation of a fixing laser beam when prescribed time elapses after starting the transfer by a fixing part 2, whereby the toner image is fixed on the recording paper 5. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electrophotographic copying machine, a printer, a facsimile (FAX) apparatus, a digital, which includes a fixing unit that melts the toner of an unfixed toner image transferred onto a recording paper by heat and penetrates and fixes the toner on the recording paper. The present invention relates to an image forming apparatus such as a multifunction peripheral.

An electrophotographic image forming apparatus such as a copying machine, a printer, a facsimile (FAX) apparatus, a digital multi-function peripheral, and the like, an image forming unit that transfers a monochrome or color toner image onto a recording paper, and the image forming unit And a fixing unit that performs a process (hereinafter, simply referred to as “fixing process”) for melting and infiltrating and fixing the toner of the unfixed toner image on the recording paper.
As a method of fixing processing performed in the fixing unit, a heat pressure fixing method using a fixing roller having a heat source and a pressure roller or a belt that is in pressure contact with the fixing roller is generally used. In the hot-pressure fixing method, the fixing roller that has generated heat rotates while pinching the recording paper at the nip portion with the pressure roller or belt, and the fixing processing is performed by feeding the recording paper downstream in the conveying direction while heating and pressing. Do.

However, in the case of this hot-pressure fixing method, the fixing roller heats not only the toner on the recording paper but also the entire recording paper. In addition, the fixing roller heats a portion of the pressure roller or the belt that does not convey the recording paper (a portion corresponding to a non-sheet passing region other than the interval between the sheets or the width of the sheet). Since the heat energy for heating these parts other than the toner does not directly contribute to the melting and fixing of the toner, the fixing process by this method causes a loss of heat energy.
In the case of the hot-pressure fixing method, the heat source of the fixing roller is heated even when the fixing process is not actually performed, such as when the image forming apparatus is started up or during standby, so that the surface temperature of the fixing roller can be reduced in a short time. It was necessary to maintain a predetermined temperature suitable for the fixing process. Nevertheless, when the image forming apparatus is started up, the user has to wait for printing until the fixing roller reaches a predetermined temperature.

Therefore, as a new fixing process method that improves these points, a fixing process in which heat energy is selectively applied only to the portion of the recording paper (or transfer body, transfer fixing body) to which the toner image has been transferred is employed. For example, as described in Patent Document 1, a recording sheet on which a toner image is transferred is wound around a fixing drum, and formed on a recording sheet by a signal from a leading end detection sensor that detects the leading end of the recording sheet. There is a fixing device that scans a fixing laser in synchronization with a portion of an unfixed toner image and fixes the toner of the toner image on a recording sheet.

In this fixing device, a cleaning device is provided downstream of the fixing laser irradiation position in the rotation direction of the fixing drum, and the unfixed toner remaining on the recording paper after fixing is removed by the cleaning device. Therefore, it is possible to prevent the recording paper from being stained.

  However, when the thermal energy is selectively applied only to the portion where the toner image on the recording paper is transferred, the position of the toner image transferred onto the recording paper and the heating position where the thermal energy is applied are misaligned. As a result, a part of the toner image on the recording paper becomes unfixed and the image quality of the image formed on the recording paper is deteriorated.

  In an image forming apparatus for fixing a toner image onto a recording sheet by irradiating a conventional fixing laser as described in Patent Document 1, after the toner is transferred to the recording sheet, the recording sheet is fixed to the fixing apparatus. Since the recording paper is wound around the fixing drum and subjected to fixing processing, slip and skew are likely to occur in the conveying path from the position where the recording paper is transferred to the fixing drum to be fixed. The conveyance trajectory is also likely to vary. Therefore, there is a problem that it is difficult to irradiate the fixing laser with high accuracy in synchronization with the unfixed toner image portion on the recording paper.

  The present invention has been made in view of the above-mentioned problems, and improves the thermal efficiency of the fixing process and prevents slips, skews, variations in the conveyance path, and the like during conveyance of the recording paper onto which the toner image is transferred. Thus, an object of the present invention is to reduce the deviation between the position of the unfixed toner image on the recording paper and the selective heating position so that a high-quality image can be obtained.

The present invention relates to a conveying unit that conveys a recording sheet, a transfer unit that transfers a toner image formed on a photosensitive member to the recording sheet conveyed by the conveying unit, and an unfixed toner image transferred by the transferring unit. In order to achieve the above object, an image forming apparatus provided with fixing means for fixing the toner image on the recording paper is configured as follows.
That is, the transport unit is a close-contact transport unit that transports the recording paper in close contact with the transport member, and the fixing unit is located downstream of the transfer unit of the close-contact transport unit in the transport direction of the recording paper. Means for selectively heating the entire area or a predetermined area of the recording paper conveyed in close contact with the conveying member.

It is desirable that the area of the recording paper that is selectively heated by the fixing unit substantially coincides with the area where the toner image is transferred. Further, laser light irradiation means may be used as the fixing means.
Further, once the conveyance of the recording paper is temporarily stopped upstream of the transfer unit in the conveyance direction of the recording paper, the image formation start position for the recording paper is the leading edge of the toner image formed on the photosensitive member. It is preferable to provide a registration roller that conveys the recording paper to the transfer position at the same timing at the transfer position by the transfer means.
This registration roller can be provided at a predetermined position upstream of the transfer position on the conveying member of the close-contact conveying means in the recording paper conveyance direction.

Further, the close-contact conveyance means may be provided with a charge imparting means for charging the recording paper in order to electrostatically attract the recording paper to the conveyance member. Then, the charging means can be provided at a position upstream of the transfer position of the transfer means in the contact direction of the recording paper with respect to the transfer position.
Further, the close-contact conveying means is provided with a recording paper detecting means for detecting the leading edge of the recording paper, and the fixing means detects the leading edge of the recording paper after the recording paper detecting means detects the leading edge of the recording paper. The recording paper conveyed in close contact may be heated.

  The recording paper detection means may be provided between the transfer position by the transfer means and the selective heating position by the fixing means. Further, another recording paper detection means is provided upstream of the transfer position of the contact conveyance means by the transfer means in the recording paper conveyance direction, and when the recording paper detection means detects the leading edge of the recording paper, a laser is applied to the photosensitive member. You may make it start writing of the image by light.

Alternatively, a predetermined image pattern is provided in a portion outside the sheet passing area on the conveying member of the close-contact conveying means or between the recording sheets, and an image pattern detecting means for detecting the image pattern is provided in the fixing portion of the close-contact conveying means, and the fixing The means may heat the recording paper conveyed in close contact with the conveying member after a predetermined time has elapsed since the image pattern detecting means detected the image pattern.
The image pattern detection means may be provided between the transfer position by the transfer means and the selective heating position by the fixing means.

Further, it is desirable to provide unfixed toner collecting means for collecting unfixed toner remaining on the surface of the recording paper on which the toner image is fixed, on the downstream side in the conveyance direction of the recording paper with respect to the fixing means.
The unfixed toner collecting means is provided with a contact member that contacts the surface of the recording paper on which the toner image of the recording paper is fixed by applying a voltage having a polarity opposite to that of the unfixed toner, and electrostatically attracts the unfixed toner. Then, it is good to use as a means to collect.

The contact member may be a rotating body, and a pressure rotating body may be provided that is in rolling contact with the rotating body with a recording sheet interposed therebetween. It is also possible to provide the rotating body on the conveying member of the close-contact conveying means and also use the rotating body of the close-contact conveying means as the pressure rotating body.
As described above, when an unfixed toner collecting unit for electrostatically attracting and collecting unfixed toner is provided, on the recording paper transferred by the transfer unit on the upstream side of the unfixed toner collecting unit in the recording paper transport direction or It is more preferable to provide charging means for charging the toner on the intermediate transfer material to the same polarity.

  According to the present invention, the thermal efficiency of the fixing process is increased and there is almost no slip, skew, or variation in the conveyance path during the conveyance of the recording paper on which the toner image is transferred. The deviation between the position and the selective heating position is reduced, and a high-quality image is obtained.

Preferred embodiments of the present invention will be described below with reference to the drawings.
[First embodiment]
FIG. 1 is a block diagram schematically showing an essential part of a first embodiment of an image forming apparatus according to the present invention. In FIG. 1, only the portion related to the present invention in the vicinity of the image forming portion of the image forming apparatus is shown, and other portions such as a paper feeding portion, an image reading portion, and an image writing portion are not shown. . The same applies to the following FIGS. 2 to 8 and FIGS. 10 to 19.

This image forming apparatus is a monochrome image forming apparatus, and includes an image forming unit 1, a fixing unit 2 that is a fixing unit, a transport unit 3 that is a close-contact transport unit, and a pair of registration rollers 4.
The image forming unit 1 includes a drum-shaped photoconductor 11, a charging roller 12, a developing device 13, a transfer roller 14, and a cleaning device 15 disposed around the drum-shaped photoconductor 11, an exposure unit of an image writing unit (not shown), and the like. .

The conveyance unit 3 includes a pair of grounding rollers 32 and 33 disposed at a position near the upstream registration roller 4 in the conveyance direction of the recording paper and a downstream fixing position, and a conveyance member stretched therebetween. The grounding rollers 32 and 33 are made of metal and are grounded.
The transfer roller 14 is provided inside the transfer belt 31 so as to sandwich the photoreceptor 11 and the transfer belt 31, and a positive (+) voltage is applied by the power source E1. The transfer roller 14 and the transfer belt 31 constitute transfer means. The transfer belt 31 is an endless belt made of a non-conductive material having a width wider than the usable recording paper.

  In addition, a charging roller 17 serving as a charging unit is provided on the upper side of the transfer roller 31 with respect to the ground roller 32 on the upstream side of the conveying unit 3, and a positive (+) voltage is applied by the power source E <b> 2. The voltage applied to the charging roller 17 may be direct current, alternating current, or a combination thereof. In this embodiment, the negatively charged toner is transferred to the recording paper by a positive transfer electric field. Yes.

  In the image forming unit 1, the drum-shaped photoconductor 11 rotates in the direction of arrow A during image formation, and the surface of the photoconductor 11 is made uniform by a charging roller 12 to which a charging voltage is applied by a high voltage power source (not shown). To charge. The surface of the charged photoconductor 11 is exposed by a writing laser beam L1 emitted from an exposure unit of an image writing unit (not shown) to form an electrostatic latent image on the surface of the photoconductor 11.

  The writing laser beam L1 is turned on / off based on image data of an image to be formed. The image data is, for example, image data obtained by an image reading unit optically reading an image of a document and converting it into an electrical signal, or Image data received from an external device such as a personal computer connected to the image forming apparatus. Usually, the image forming apparatus temporarily stores read image data or received image data in an image memory, and then reads out necessary image data from the image memory to perform image formation.

The electrostatic latent image formed on the photoconductor 11 is developed with toner as a developer attached by the developing device 13, and a toner image is formed on the surface of the photoconductor 11.
On the other hand, a recording sheet (transfer sheet) 5 fed from a sheet feeding unit (not shown) is sandwiched between registration rollers 4 and stopped at one end. Thereafter, an image formation start position with respect to the recording sheet 5 is a photosensitive member 11. The top of the toner image formed above is conveyed to the conveyance unit 3 by the registration roller 4 so that it coincides with a transfer position P that is a nip portion between the photoconductor 11 and the transfer roller 14.

The registration roller 4 is desirably a roller having a small diameter (preferably φ16 or less) in order to prevent the recording paper 5 from being wound. Furthermore, it is advisable to take preventive measures to prevent paper dust and dust from adhering. For example, a release device is provided on the surface of the roller, or a removing means such as paper dust or dust is provided.
The recording paper 5 is positively charged by the charging roller 17, and the recording paper 5 is attracted and brought into close contact with the transfer belt 31 that also serves as a conveying member that is grounded by the ground roller 32, and is transferred by a drive motor (not shown). The belt 31 is conveyed in the same direction as the belt 31 rotates in the arrow B direction.

Then, the image formation start position on the recording paper 5 coincides with the leading end of the toner image formed on the photoconductor 11 at the transfer position P, and the toner image on the photoconductor 11 is moved by the action of the transfer electric field by the transfer roller 14. Transferred onto the recording paper 5.
The toner remaining on the surface of the photoconductor 11 after the transfer is removed by the cleaning device 15, and the residual charge on the surface of the photoconductor 11 is also removed by a neutralizing device (not shown) to prepare for the next image formation.

  Incidentally, the charging roller 17 needs to be provided upstream of the selective heating position D by the fixing unit 2 in the recording paper conveyance direction (right side in FIG. 1). However, as in this embodiment, the transfer roller 14 and the like. It is preferable to dispose further upstream of the transfer position P in the transport direction. In this way, since the recording paper 5 can be transported to the transfer position P in a state in which the recording paper 5 is previously attracted to the transfer belt 31 (contact state), it is possible to prevent slipping while the recording paper 5 is transported to the transfer position P. The toner image can be transferred to an accurate position on the recording paper 5.

  Next, the fixing unit 2 will be described. The fixing unit 2 which is a fixing unit in this embodiment is a laser beam irradiation unit, and is at a selective heating position D downstream of the transfer position P on the transport unit 3 in the recording paper transport direction (left side in FIG. 1). Then, the entire area or a predetermined area of the recording paper 5 conveyed in close contact with the transfer belt 31 is heated by selectively irradiating the fixing laser beam L2, and the unfixed toner on the recording paper 5 is melted. Let it settle.

  At this time, the fixing unit 2 generates the fixing laser beam L2 based on the image data based on the writing laser beam L1 described above, that is, the image data of the toner image transferred to the recording paper 5 by the imaging unit 1. The recording paper 5 may be irradiated at a predetermined timing. The predetermined timing in this case is the timing at which the leading edge of the toner image on the recording paper 5 reaches the selective heating position D after the recording paper 5 is started to be conveyed by the registration roller 4. However, the irradiation of the fixing laser beam L2 is started at that timing.

In this way, the predetermined area on the recording paper 5 that is selectively heated by the fixing laser beam L2 and the area on the recording paper 5 to which the toner image has been transferred can be substantially matched.
In FIG. 1, in order to make the distinction between the unfixed toner T1 and the fixed toner T2 on the recording paper 5 easy to understand, the thickness is emphasized and varied, but the actual toner The thickness is very thin compared to the paper thickness of the recording paper, regardless of whether it is unfixed or fixed.

The recording paper 5 on which the toner image has been fixed is conveyed by a discharge roller (not shown) and discharged to the outside of the image forming apparatus, or is conveyed again to the registration roller 4 through the double-sided conveyance path, and the above-described The image forming sequence is repeated to form an image on the back side.
According to this embodiment, since the transfer process and the fixing process can be performed while transporting the recording paper in close contact with the transfer belt 31 as a transport member, slipping can occur even in the transport path from the transfer position P to the selective heating position D. No skew occurs and the recording paper transport locus does not vary.

Therefore, it is difficult for the position of the toner image transferred onto the recording paper and the position where the heat energy is applied by the fixing unit to be difficult to prevent a part of the toner image on the recording paper from being unfixed and degrading the image quality. Can do.
Furthermore, it becomes easy to irradiate the fixing laser in synchronism with the unfixed toner T1 on the recording paper with high accuracy, and only the portion to be heated on the recording paper can be selectively heated. It is also possible to suppress the loss of heat energy due to heating to useless parts that are not related.

  In this embodiment, the case where the fixing process is performed by irradiating the toner image on the recording paper with the fixing laser beam using the laser beam irradiating unit in the fixing unit 2 has been described. However, the fixing means is not limited to this, and for example, a thermal head, an energization heating element divided into cells, or a plurality of lamps regularly arranged may be used. Even in this case, a predetermined region of the recording paper can be selectively heated.

  Further, if these fixing units heat only the toner image on the recording paper, there is no loss of useless heat energy, and the thermal efficiency of the fixing process can be further increased. However, the predetermined area of the recording paper P that is selectively heated by the fixing unit is not limited to an area that substantially coincides with the position where the toner image is transferred. For example, when an image is formed over substantially the entire area of the recording paper, the entire area of the recording paper may be heated. Even in such a case, the fixing unit does not heat the non-sheet passing area of the transfer belt 31 and the portion corresponding to the space between the recording sheets, so that it is possible to suppress the consumption of useless heat energy.

Furthermore, in this embodiment, as an example of means for bringing the recording paper 5 into close contact with the transfer belt 31, the charging roller 17 is provided at a position facing the grounding roller 32 with the transfer belt 31 interposed therebetween, but the present invention is not limited to this. As long as the position is in contact with the recording paper on the upstream side of the selective heating position D in the conveyance direction of the recording paper, the position may be provided anywhere. However, as described above, it is better to provide it as upstream as possible in the recording paper conveyance direction.
Further, the recording paper may be charged by using a charging means such as an elastic metal piece other than the charging roller or a conductive brush. Further, the recording paper may be attracted to the transport member by negative pressure without using the charging means, or the recording paper may be fixed to the transport member by clamping with a claw.

  In this embodiment, the case where the registration roller 4 is disposed upstream of the conveyance unit 3 in the conveyance direction of the recording paper has been described. However, the registration roller 4 is not essential to the present invention. For example, in the case where the transfer timing in the image forming unit may be slightly shifted such as when the recording paper is continuous paper, the registration roller may not be provided. Alternatively, the registration roller 4 may be provided in the conveyance unit 3 and the transfer belt 31 may be sandwiched by the nip portion. Further, as in an embodiment shown in FIG. 5 described later, the ground roller 32 and the charging roller 17 may also function as a registration roller.

[Second Embodiment]
Next, a description will be given of a second embodiment of the image forming apparatus according to the present invention. FIG. 2 is a block diagram similar to FIG. 1 of the image forming apparatus, and the same reference numerals are given to portions corresponding to those in FIG. 1, and description thereof is omitted.

  This image forming apparatus has a quadruple tandem color system in which four image forming units having the same configuration as the image forming unit 1 shown in FIG. 1 are provided in a line along the transfer belt 31 of the conveying unit 3. An image forming apparatus. The image forming units 1M, 1C, 1Y, and 1K are for magenta, cyan, yellow, and black, respectively. Although only the drum-shaped photoconductor 11 and the transfer roller 14 are shown, in reality, the charging roller 12, the developing device 13, and the cleaning device 15 shown in FIG. 1 are also provided. Only the color of the toner stored in the developing device 13 differs from magenta, cyan, yellow, and black by the image forming units 1M, 1C, 1Y, and 1K.

  The photoreceptors 11 of the image forming units 1M, 1C, 1Y, and 1K are uniformly charged on the surface by a charging roller (not shown), and then written in accordance with the image components of magenta, cyan, yellow, and black. The electrostatic latent images are formed by irradiation of the embedded laser beams LM, LC, LY, and LK, and are developed by developing devices for each color (not shown), and magenta, cyan, yellow, and black toner images are formed on the surface. Is formed.

On the other hand, the recording paper 5 conveyed to the conveying unit 3 at a predetermined timing by the pair of registration rollers 4 is charged by the charging roller 17 as in the case of the first embodiment, and is attracted to the transfer belt 31 and indicated by an arrow B. The toner images of magenta, cyan, yellow, and black are sequentially superimposed and transferred at a transfer position that is a nip portion between the photoreceptor 11 and the transfer roller 14 of each of the image forming units 1M, 1C, 1Y, and 1K. Is done.
Thereafter, the recording paper 5 is conveyed to the fixing unit 2 while being in close contact with the transfer belt 31, and the fixing laser light L <b> 2 is selectively irradiated at the selective heating position D by the fixing unit 2, and unfixed on the recording paper 5. Four color toners are heated and fixed.

  Accordingly, in the case of this color image forming apparatus, as in the case of the image forming apparatus of the first embodiment shown in FIG. 1, transfer processing and fixing are performed while the recording paper 5 is conveyed in a state of being in close contact with the transfer belt 31. Since the processing can be performed, the position of the color toner image transferred onto the recording paper 5 and the selective heating position are not easily misaligned. Therefore, a high-quality color image can be obtained while suppressing loss of heat energy.

[Third embodiment]
Next, a description will be given of a third embodiment of the image forming apparatus according to the present invention. FIG. 3 is a block diagram schematically showing the main part of the image forming apparatus, and the same reference numerals are given to the parts corresponding to those in FIG. This is a transfer drum type color image forming apparatus, which is provided with a transport unit 6 including a transfer drum 35 which also serves as a transport member of a close-contact transport unit in place of the transport unit 3 in the first embodiment shown in FIG. Yes. The transfer drum 35 rotates in the direction indicated by arrow F, and the transfer roller 14 is brought into contact with the inner peripheral surface of the transfer drum 14 so as to face the drum-shaped photoconductor 11. A grounding roller 36 is provided at the corresponding inner peripheral position, and the transfer drum 35 is set to the ground potential.

  Further, a charging roller 17 is disposed opposite to the position where the recording paper 5 is conveyed by the registration roller 4 on the outer peripheral surface of the transfer drum 35, and the recording paper 5 conveyed by the registration roller 4 is charged to a positive potential. Then, the recording paper is brought into close contact with the transfer drum 35 that is rotated to the ground potential by the ground roller 36.

A revolver type developing device 16 is disposed on the opposite side of the photosensitive drum 11 from the transfer drum 35. In this developing device, four developing devices 16M, 16C, 16Y, and 16K respectively containing magenta, cyan, yellow, and black toners are attached to a rotating member, and are sequentially switched to a position approaching the photoconductor 11. It can be moved.
As shown in FIG. 1, a charging roller 12 and a cleaning device 15 are also provided around the photoconductor 11, but illustration thereof is omitted.

  In this image forming apparatus, electrostatic latent images corresponding to magenta, cyan, yellow, and black image components are sequentially formed on the surface of the photoconductor 11, and the electrostatic latent images are formed in the developing units 16 M, 16 of the revolver type developing device 16. The toner image is developed in order by 16C, 16Y, and 16K, and the toner image is conveyed to the transfer drum 35 by the registration roller 4 at a predetermined timing. Are transferred one by one at the transfer position where the transfer roller 14 and the transfer roller 14 face each other, and the recording paper 5 is circulated and passed through the transfer position P four times to superimpose the four color toner images, and then the selected superheat position D Then, the fixing unit 2 irradiates the fixing laser beam to heat and fix the toner image.

  Accordingly, in the case of this color image forming apparatus, as in the case of the image forming apparatus of the first embodiment shown in FIG. 1, transfer processing and fixing are performed while the recording paper 5 is conveyed in a state of being in close contact with the transfer drum 35. Since the processing can be performed, the position of the color toner image transferred onto the recording paper 5 and the selective heating position are not easily misaligned. Therefore, a high-quality color image can be obtained while suppressing loss of heat energy.

[Fourth embodiment]
Next, a description will be given of a fourth embodiment of the image forming apparatus according to the present invention. FIG. 4 is a block diagram schematically showing the main part of the image forming apparatus. The same reference numerals are given to the portions corresponding to those in FIGS.
This image forming apparatus is a color image forming apparatus that uses an intermediate transfer belt in a quadruple tandem system. The four image forming sections 1M, 1C, 1Y, and 1K have the same configuration as the second embodiment shown in FIG. The magenta, cyan, yellow, and black toner images thus formed are not directly transferred to the recording paper 5, but are intermediately transferred between the ground roller 41 and the charging roller 42 (in the direction indicated by the arrow G). Are transferred to the lower surface of the sheet.

The grounding roller 41 that stretches the intermediate transfer belt 40 is grounded, and a negative voltage is applied to the charging roller 42 to also serve as a charge applying unit.
The recording sheet 5 conveyed to the conveying unit 3 at a predetermined timing by the registration roller 4 is sandwiched between the roller 32 ′ and the charging roller 42 of the conveying unit 3 and charged to a negative potential. Is attracted to the transfer belt 31 charged to a positive potential by the roller 32 'to which is applied, and is closely conveyed in the direction of arrow H. At that time, the roller 32 ′ functions as a transfer roller, and the color toner images on the intermediate transfer belt 40 are collectively transferred onto the recording paper 5.

When the recording paper 5 on which the color toner image has been transferred passes through the selective heating position D on the transport unit 3, the fixing laser beam L2 is irradiated by the fixing unit 2 and the region where the toner image is transferred is selectively selected. Is fixed by heating.
Also according to this embodiment, the same operational effects as those of the respective embodiments described above can be obtained.

[Fifth embodiment]
FIG. 5 is a block diagram schematically showing the main part of a fifth embodiment of the image forming apparatus according to the present invention. In this image forming apparatus, the registration roller 4 in FIG. 1 is omitted, and the grounding roller 32 of the transport unit 3 and the charging roller 17 facing the transfer belt 31 sandwiching the transfer roller 31 also serve as a registration roller. Except for this, it is the same as the first embodiment.

In this case, when the recording paper 5 is put on standby, the rotation of the charging roller 17 is stopped and fixed, and the recording paper 5 is pushed and slipped, or the charging roller 17 is reversed to prevent the recording paper 5 from entering the nip portion. How to make it.
In this manner, the fixing unit 2 fixes the recording paper 5 from the start of conveyance based on the distance x between the nip portion between the charging roller 17 and the ground roller 32 and the selective heating position D and the conveyance speed v by the transfer belt 31. The timing t at which the irradiation of the laser beam L2 is started can be accurately calculated from t = x / v. Other functions and effects are the same as those of the first embodiment shown in FIG.

[Sixth embodiment]
FIG. 6 is a block diagram schematically showing the main part of a sixth embodiment of the image forming apparatus according to the present invention. This image forming apparatus is a quadruple tandem type color image forming apparatus similar to that of the second embodiment shown in FIG. 2. The registration roller 4 in FIG. 2 is omitted, and the grounding roller 32 of the transport unit 3 and the transfer belt 31. This is the same as that of the first embodiment except that the charging roller 17 that is opposed to the charging roller 17 also functions as a registration roller. The function of the registration roller by the charging roller 17 and the ground roller is the same as that of the fifth embodiment described above with reference to FIG.

[Seventh embodiment]
FIG. 7 is a block diagram schematically showing the main part of a seventh embodiment of the image forming apparatus according to the present invention. This image forming apparatus is the same color image forming apparatus of the transfer drum type as that of the third embodiment shown in FIG. 3. The registration roller 4 in FIG. 3 is omitted, and the transfer drum 35 and the charging roller 17 serving as a charge applying unit. This is the same as the third embodiment except that it also functions as a registration roller. The function of the registration roller by the charging roller 17 and the ground roller is the same as that of the fifth embodiment described above with reference to FIG.

[Eighth embodiment]
Next, an eighth embodiment of the image forming apparatus according to the present invention will be described with reference to FIGS. FIG. 8 is a configuration diagram similar to FIG. 1 schematically showing the main part of the image forming apparatus, and FIG. 9 is a schematic plan view showing the arrangement relationship of the transfer belt, the recording paper, and the recording paper detection sensor. is there. In these drawings, the same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted.

  In the eighth embodiment, the first sheet detection sensor 21 is fixed at a predetermined position just downstream of the charging roller 17 at the center in the width direction on the upper side of the transfer belt 31 of the conveying unit 3 serving as a close-contact conveying unit. A second paper detection sensor 22 is disposed at a predetermined position immediately upstream of the selective heating position D by the unit 2. As these first and second paper detection sensors 21 and 22, reflection type photosensors are used, and they are arranged at a distance L in the conveyance direction of the recording paper 5. V indicates the conveyance speed by the transfer belt 31.

  Then, after the recording paper 5 is conveyed to the conveying unit 3 by the registration roller 4, when the first paper detection sensor 21 detects the passage of the leading edge of the recording paper 5, the image by the writing laser beam L <b> 1 on the photoconductor 11. Is started, and after a predetermined time has elapsed since the second paper detection sensor 22 detected the passage of the leading edge of the recording paper 5, the fixing unit 2 irradiates the fixing laser light L2 and the image portion of the recording paper 5 6 is heated to fix the toner image transferred thereto.

At this time, the above-described predetermined time is set so that the image portion 6 on the recording paper 5 and the area irradiated with the fixing laser light L2 coincide. In this image forming apparatus, the positional deviation between the image portion 6 and the irradiation area of the fixing laser beam L2 is close to the color deviation accuracy of a color image, and is about brass / minus 150 μm.
In this embodiment, the second paper detection sensor 22 is a recording paper detection means necessary for controlling the operation of the fixing unit 2, and the first paper detection sensor 21 is another recording for controlling the start of image writing. It is a paper detection means. When the registration roller 4 is provided, the first paper detection sensor 21 may not be provided.

[Ninth embodiment]
FIG. 10 is a block diagram schematically showing the main part of the ninth embodiment of the image forming apparatus according to the present invention. The same parts as those in FIGS. .
In this embodiment, the quadruple tandem type color image forming apparatus shown in FIG. 2 is provided with the first and second paper detection sensors 21 and 22 as in the eighth embodiment shown in FIGS. It is a thing. The image writing start and the irradiation start of the fixing laser beam L2 based on the leading edge detection signals of the recording paper 5 by the first and second paper detection sensors 21 and 22 are the same as in the eighth embodiment, and the operation thereof The effect is the same.

[Tenth embodiment]
FIG. 11 is a block diagram schematically showing the main part of the tenth embodiment of the image forming apparatus according to the present invention. The same parts as those in FIGS. Omitted.
This embodiment is the same as the eighth embodiment shown in FIGS. 8 and 9 in the color image forming apparatus using the transfer drum and the revolver type developing device shown in FIG. Sensors 21 and 22 are provided close to the outer periphery of the transfer drum 35. The image writing start and the irradiation start of the fixing laser beam L2 based on the leading edge detection signals of the recording paper 5 by the first and second paper detection sensors 21 and 22 are the same as in the eighth embodiment, and the operation thereof The effect is the same. In this embodiment, the transfer roller 14 in the third embodiment shown in FIG. 3 is omitted, and a positive voltage is applied to the support of the transfer drum 35 by the power supply E1.

[Eleventh embodiment]
Next, an eleventh embodiment of the image forming apparatus of the present invention will be described. FIG. 12 is a block diagram schematically showing the main part of the image forming apparatus. The same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.
In this embodiment, in the monochrome image forming apparatus shown in FIG. 1, fixing is not performed in the fixing step by heating the selected area by the fixing unit 2, and unfixed toner remaining on the recording paper (occurs in a background portion or an abnormal image). ) To collect unfixed toner.

In this embodiment, as the unfixed toner collecting means, a voltage having a polarity opposite to the charging polarity of the unfixed toner is applied, and the toner image of the recording paper 5 is located downstream of the selective heating position D in the transport direction of the recording paper 5. Is provided with an abutting member that abuts the surface on which the toner is fixed (the upper surface in the illustrated example) and electrostatically adsorbs and collects the unfixed toner on the recording paper.
This will be described with reference to FIG. 12. A collection roller 26, which is a rotating body, is brought into contact with the surface (upper surface in the drawing) of the recording paper 5 near the rear end of the transport unit 3 as a contact member. A positive (+) voltage is applied thereto by a power source E6. In this example, since the unfixed toner is negatively (−) charged, a positive voltage having a polarity opposite to the charged polarity is applied.

  In this embodiment, a pressure roller 25, which is a pressure rotator that is in rolling contact with the collection roller 26 with the recording paper 5 interposed therebetween, is provided and grounded. Further, a blade 27 that contacts the upper outer peripheral surface of the recovery roller 26 and a recovery container (not shown) are also provided, and unfixed toner recovered by electrostatic adsorption from the recording paper 5 to the outer peripheral surface of the recovery roller 26 is scraped by the blade 27. Take it into a collection container.

  Since the recording paper 5 is charged positively by the transfer roller 14 at the transfer portion, it does not wrap around the collecting roller 26 to which a positive voltage is applied. The rotating body as the contact member may be an endless belt instead of the collection roller 26. The pressure roller 25, which is a pressure rotator, is preferably a metal roller whose surface is covered with a fluororesin.

  Further, in this embodiment, the toner on the recording paper transferred by the transfer means such as the transfer roller 14 has the same polarity (in this example, the negative electrode) on the upstream side in the recording paper transport direction from the recovery roller 26 of the unfixed toner recovery means. A charger 24 and a power source E5 for applying a negative voltage to the charger 24 are provided as charging means. The voltage applied to the charger 24 may be the same polarity as the charging polarity of the toner in the developing device 13.

This is because the polarity of the toner after development and transfer is not always constant, and a small amount of reverse polarity toner is also mixed, so by charging the toner after transfer to the same polarity, This is so that the unfixed toner can be more reliably adsorbed and collected by the collecting roller 26 to which a voltage having a polarity opposite to the charging polarity is applied.
According to this embodiment, unfixed toner does not remain on the discharged recording paper, and there is no possibility that the user's hand or clothes are soiled or the image quality is deteriorated.

[Twelfth embodiment]
FIG. 13 is a block diagram schematically showing the main part of the twelfth embodiment of the image forming apparatus according to the present invention. The same parts as those in FIGS. .
This embodiment is similar to the eleventh embodiment shown in FIG. 12 in the quadruple tandem type color image forming apparatus shown in FIG. 2, and is a recovery roller 26, a power source E6, and a pressure roller as unfixed toner recovery means. 25 and a blade 27, and a charger 24 and a power source E5 are provided as charging means, and the function and effect thereof are the same as those of the eleventh embodiment.

[Thirteenth embodiment]
FIG. 14 is a block diagram schematically showing an essential part of a thirteenth embodiment of the image forming apparatus according to the present invention. Parts corresponding to those in FIGS. 3 and 12 are denoted by the same reference numerals, and description thereof is omitted. To do.
This embodiment is similar to the eleventh embodiment shown in FIG. 12 in the color image forming apparatus using the transfer drum and the revolver type developing device shown in FIG. A power supply E6, a pressure roller 25, and a blade 27 are provided, and a charger 24 and a power supply E5 are provided as charging means. The operation and effects thereof are the same as those of the eleventh embodiment.

[14th embodiment]
FIG. 15 is a block diagram schematically showing a main part of a fourteenth embodiment of the image forming apparatus according to the present invention. Parts corresponding to those in FIGS. 4 and 12 are denoted by the same reference numerals, and description thereof is omitted. To do.
In this embodiment, an unfixed toner collecting means is provided in the quadruple tandem type color image forming apparatus using the intermediate transfer belt shown in FIG. 4 as in the eleventh embodiment shown in FIG. It is provided on the downstream side of the selective heating position D on the transfer belt 31 that also serves as a conveying member of the conveying unit 3 that is a close-conveying means.

  That is, as shown in FIG. 15, the collection roller 26 is brought into close contact with the transfer belt 31 and conveyed in the direction indicated by the arrow H at a position facing the grounding roller 33 at the rear end of the conveyance unit 3 with the transfer belt 31 in between. A surface of the recording paper 5 on which the toner image is fixed is provided so as to come into contact with the surface, and a positive voltage having a polarity opposite to the toner charging polarity is applied to the collecting roller 26 by a power source E6. Further, a blade 27 is also provided that is in sliding contact with the outer peripheral surface of the collection roller 26. A grounding roller 33 that stretches the transfer belt 31 is also used as a pressure roller.

By doing this, it is possible to collect unfixed toner on the recording paper and not leave it on the recording paper, as in the above-described first to thirteenth embodiments. In addition, it is not necessary to provide a separate pressure roller, and the collection roller 26 and the like are provided on the transport unit 3, so that the size and cost can be reduced.
In this embodiment, a negative voltage is applied by the power source E5 on the downstream side of the four image forming units 1M, 1C, 1Y, and 1K in the vicinity of the intermediate transfer belt 40 (the lower surface in FIG. 16). The charger 24 is arranged to charge the toner transferred by the transfer means to the same polarity (in this example, negative polarity), so that the recovery efficiency of the unfixed toner by the recovery roller 26 is increased.

[Fifteenth embodiment]
FIG. 16 is a block diagram schematically showing the principal part of the fifteenth embodiment of the image forming apparatus according to the present invention. The same parts as those in FIGS. .
In this embodiment, as in the eleventh embodiment shown in FIG. 12, the monochrome image forming apparatus shown in FIG. 1 is provided with unfixed toner collecting means, but the collecting roller 26 is a close-contact conveying means. It is provided at a position facing the grounding roller 33 of the transport unit 3 across the transfer belt 31, and the grounding roller 33 is also used as a pressure roller. Further, the charger 24 and the power source E5 provided in the eleventh embodiment of FIG. 12 are omitted.
Even in this case, the unfixed toner on the recording paper 5 can be collected as in the eleventh embodiment, and the size and cost can be reduced.

[Sixteenth embodiment]
FIG. 17 is a block diagram schematically showing the main part of the sixteenth embodiment of the image forming apparatus according to the present invention. The same parts as those in FIGS. .
In this embodiment, as in the twelfth embodiment shown in FIG. 13, the unfixed toner collecting means is provided in the quadruple tandem type color image forming apparatus shown in FIG. The contact roller 3 is provided at a position facing the ground roller 33 of the transport unit 3 that is a close contact transport unit with the transfer belt 31 interposed therebetween, and the ground roller 33 is also used as a pressure roller. Further, the charger 24 and the power source E5 provided in the twelfth embodiment of FIG. 13 are omitted.
Even in this case, the unfixed toner on the recording paper 5 can be collected as in the twelfth embodiment, and the size and cost can be reduced.

[Seventeenth embodiment]
FIG. 18 is a block diagram schematically showing an essential part of a seventeenth embodiment of the image forming apparatus according to the present invention. The same parts as those in FIGS. 3 and 14 are denoted by the same reference numerals, and description thereof is omitted. .
In this embodiment, as in the thirteenth embodiment shown in FIG. 14, the unfixed toner collecting means is provided in the color image forming apparatus using the transfer drum and the revolver type developing device shown in FIG. The collection roller 26 is provided at a position facing the ground roller 36 of the transport unit 3 serving as a close-contact transport unit with the transfer drum 35 interposed therebetween, and the ground roller 36 is also used as a pressure roller. Further, the charger 24 and the power source E5 provided in the thirteenth embodiment of FIG. 14 are omitted.

Even in this case, the unfixed toner on the recording paper 5 can be collected as in the twelfth embodiment, and the size and cost can be reduced.
In this embodiment as well, the registration roller 4 in the third embodiment of FIG. 3 is omitted, the charging roller 17 is also used as the registration roller, the transfer roller 14 is also omitted, and the support of the transfer drum 35 is positively connected by the power source E1. A voltage is applied. By doing so, further miniaturization and cost reduction are achieved.

[Eighteenth embodiment]
Next, an eighteenth embodiment of the image forming apparatus according to the present invention will be explained. FIG. 19 is a configuration diagram schematically showing the main part of the image forming apparatus. The same parts as those in FIG. 12 are denoted by the same reference numerals, and description thereof will be omitted. 20 is a schematic plan view showing the positional relationship among the transfer belt, the recording paper, the image pattern, and the pattern detection sensor in FIG. 19, and the same parts as those in FIG. Is also omitted.

In this embodiment, as in the eleventh embodiment of FIG. 12, the monochrome image forming apparatus is provided with a collection roller 26 and a pressure roller 25 constituting unfixed toner collection means, but the charger 24 and the power source E5 are omitted. doing.
Then, as shown in FIG. 20, a predetermined image pattern 7 is provided at a portion outside the sheet passing area on the transfer belt 31 that also serves as a conveying member of the conveying unit 3 that is a close-conveying means. Further, an image pattern detection sensor 23 which is an image pattern detection means for detecting the image pattern 7 is provided between the transfer position P by the transfer roller 14 and the selective heating position D by the fixing unit 2 in the fixed portion of the transport unit 3. ing. The fixing unit 2 is a recording sheet 5 that is transported in close contact with the transfer belt 31 when the fixing unit 2 irradiates the fixing laser light L2 after a predetermined time has elapsed since the image pattern detection sensor 23 detects the image pattern 7. Heat.

The predetermined time t includes the distance Ls between the image pattern 7 shown in FIG. 20 and the leading end of the image portion 6 on the recording paper 5, the moving speed v of the transfer belt 31, the position of the image pattern detection sensor 23, and the selective heating position. It is calculated by t = (Ls + α) / v from the interval α with D. As a result, the positional deviation accuracy between the irradiation region of the fixing laser light and the image portion 6 on the recording paper 5 becomes close to the color deviation accuracy of the color image forming apparatus.
An image forming apparatus, wherein the image pattern detection means is provided between a transfer position by the transfer means and a selective heating position by the fixing means.

[Nineteenth embodiment]
FIG. 21 is a schematic plan view similar to FIG. 20 of the nineteenth embodiment of the image forming apparatus according to the present invention. This embodiment is a modification of the above-described eighteenth embodiment, in which a predetermined image pattern 7 on the transfer belt 31 is formed at a portion between the recording sheets in the central portion of the transfer belt 31 in the width direction. The pattern detection sensor 23 is also different from the eighteenth embodiment only in that the pattern detection sensor 23 is provided at the center of the conveyance unit 3 in the width direction. Other configurations and operational effects are the same as those in the eighteenth embodiment, and thus the description thereof is omitted.

[Other Examples]
In addition, in the first to seventh embodiments and the twelfth to seventeenth embodiments described above, a predetermined image pattern 7 and an image pattern for detecting the same, as in the eighteenth embodiment or the nineteenth embodiment described above. A detection sensor 23 is provided, and after a predetermined time has elapsed since the image pattern detection sensor 23 detected the image pattern 7, the fixing unit 2 irradiates the fixing laser beam L2 to selectively heat the image unit 6 on the recording paper 5. You may do it.

  As described above, according to the present invention, in the image forming apparatus, only the portion of the recording paper to which the toner image has been transferred is accurately selected and heated to reliably fix the toner image, thereby obtaining a high-quality image. At the same time, it is possible to increase the thermal efficiency of the fixing process and greatly reduce wasteful energy consumption. Therefore, the present invention is extremely effective when applied to various image forming apparatuses such as an electrophotographic copying machine, a printer, a facsimile (FAX) apparatus, and a digital multifunction peripheral.

1 is a configuration diagram schematically showing a main part of a first embodiment of an image forming apparatus according to the present invention; It is a block diagram which shows typically the principal part of 2nd Example of the image forming apparatus by this invention. It is a block diagram which shows typically the principal part of 3rd Example of the image forming apparatus by this invention. It is a block diagram which shows typically the principal part of 4th Example of the image forming apparatus by this invention. It is a block diagram which shows typically the principal part of 5th Example of the image forming apparatus by this invention.

It is a block diagram which shows typically the principal part of 6th Example of the image forming apparatus by this invention. It is a block diagram which shows typically the principal part of 7th Example of the image forming apparatus by this invention. It is a block diagram which shows typically the principal part of 8th Example of the image forming apparatus by this invention. FIG. 9 is a schematic plan view showing an arrangement relationship among a transfer belt, a recording sheet, and a recording sheet detection sensor in FIG. 8. It is a block diagram which shows typically the principal part of 9th Example of the image forming apparatus by this invention.

It is a block diagram which shows typically the principal part of 10th Example of the image forming apparatus by this invention. It is a block diagram which shows typically the principal part of 11th Example of the image forming apparatus by this invention. It is a block diagram which shows typically the principal part of 12th Example of the image forming apparatus by this invention. It is a block diagram which shows typically the principal part of 13th Example of the image forming apparatus by this invention. It is a block diagram which shows typically the principal part of 14th Example of the image forming apparatus by this invention.

It is a block diagram which shows typically the principal part of 15th Example of the image forming apparatus by this invention. It is a block diagram which shows typically the principal part of 16th Example of the image forming apparatus by this invention. It is a block diagram which shows typically the principal part of 17th Example of the image forming apparatus by this invention. It is a block diagram which shows typically the principal part of 18th Example of the image forming apparatus by this invention. FIG. 20 is a schematic plan view showing the positional relationship among the transfer belt, recording paper, image pattern, and pattern detection sensor in FIG. 19. It is a typical top view which shows the modification similarly.

Explanation of symbols

1, 1M, 1C, 1Y, 1K: Image forming unit 2: Fixing unit (fixing unit) 3, 6: Conveying unit (contact conveying unit) 4: Registration roller 5: Recording paper 6: Image unit 7: Image pattern 11: Photoconductor 12: Charging roller 13, 16: Developing device 14: Transfer roller (transfer means) 15: Cleaning device 17: Charge roller (charge applying means)
21: First paper detection sensor (another recording paper detection means) 22: Second paper detection sensor (recording paper detection means) 23: Image pattern detection sensor 24: Charger (charging means) 25: Pressure roller (additional pressure) 26: Recovery roller (rotating body) 27: Blade 31: Transfer belt (conveying member) 32, 33: Grounding roller 32 ': Roller (transfer roller) 35: Transfer drum (conveying member) 36: Grounding roller 40 : Intermediate transfer belt 41: Ground roller 42: Charging roller (charge applying means) L1, LM, LC, LY, LK: Writing laser beam L2: Fixing laser beam E1, E2, E3, E4, E5, E6: Power supply P : Transfer position D: Selective heating position

Claims (17)

A transport unit that transports the recording paper; a transfer unit that transfers a toner image formed on the photoreceptor onto the recording paper transported by the transport unit; and an unfixed toner image transferred by the transfer unit. In an image forming apparatus provided with a fixing unit for fixing on paper,
The transport means is a close-contact transport means for transporting the recording paper in close contact with the transport member,
The fixing unit selects an entire area or a predetermined area of the recording paper conveyed in close contact with the conveying member of the close-contact conveying unit on the downstream side in the conveying direction of the recording paper with respect to the transfer unit in the close-contact conveying unit. An image forming apparatus characterized in that the image forming apparatus is a heating means. The image forming apparatus according to claim 1.
An image forming apparatus, wherein an area of a recording sheet that is selectively heated by the fixing unit substantially coincides with an area to which the toner image is transferred. The image forming apparatus according to claim 1 or 2,
An image forming apparatus, wherein the fixing unit is a laser beam irradiation unit. The image forming apparatus according to any one of claims 1 to 3,
After the conveyance of the recording paper is temporarily stopped on the upstream side in the conveyance direction of the recording paper with respect to the transfer means, the image formation start position for the recording paper is the leading edge of the toner image formed on the photosensitive member and the transfer An image forming apparatus provided with a registration roller for conveying the recording paper to the conveying means at a timing coincident with a transfer position by the means. The image forming apparatus according to claim 4.
An image forming apparatus, wherein the registration roller is provided at a predetermined position upstream of the transfer position on the conveying member of the close-contact conveying means in the recording paper conveyance direction. The image forming apparatus according to any one of claims 1 to 5,
The image forming apparatus according to claim 1, wherein the close-contact conveyance unit includes a charging unit that charges the recording sheet to electrostatically attract the recording sheet to the conveyance member. The image forming apparatus according to claim 6.
An image forming apparatus according to claim 1, wherein the charging unit is provided at a position upstream of the transfer position of the transfer unit in the contact conveyance unit in the conveyance direction of the recording paper. The image forming apparatus according to any one of claims 1 to 7,
The close-contact conveying means is provided with a recording paper detecting means for detecting the leading edge of the recording paper, and the fixing means is a conveying member of the close-contact conveying means after a predetermined time has elapsed since the recording paper detecting means detected the leading edge of the recording paper. An image forming apparatus characterized in that the image forming apparatus is means for heating the recording paper conveyed in close contact with the paper. The image forming apparatus according to claim 8.
An image forming apparatus, wherein the recording paper detecting means is provided between a transfer position by the transfer means and a selective heating position by the fixing means. The image forming apparatus according to claim 9.
A recording paper detection means different from the recording paper detection means is provided upstream of the transfer position of the contact conveyance means by the transfer means in the recording paper conveyance direction, and the recording paper detection means detects the leading edge of the recording paper. Sometimes, the image forming apparatus further comprises means for starting writing of an image with a laser beam on the photosensitive member. The image forming apparatus according to any one of claims 1 to 7,
A predetermined image pattern is provided at a portion outside the sheet passing area on the conveying member of the close-contact conveying means or between the recording sheets, and an image pattern detecting means for detecting the image pattern is provided at a fixing portion of the close-contact conveying means, and the fixing The image forming apparatus according to claim 1, wherein the image pattern detecting unit is a unit that heats the recording sheet conveyed in close contact with the conveying member after a predetermined time has elapsed since the image pattern detecting unit detected the image pattern. The image forming apparatus according to claim 11.
An image forming apparatus, wherein the image pattern detection means is provided between a transfer position by the transfer means and a selective heating position by the fixing means. The image forming apparatus according to any one of claims 1 to 12,
An image forming apparatus comprising: an unfixed toner collecting unit that collects unfixed toner remaining on a surface of the recording paper on which the toner image is fixed, on the downstream side of the fixing unit in the conveyance direction of the recording sheet. . The image forming apparatus according to claim 13.
The unfixed toner collecting means includes a contact member that is applied with a voltage having a polarity opposite to the charging polarity of the unfixed toner and contacts the surface of the recording paper on which the toner image is fixed, and electrostatically attracts the unfixed toner. An image forming apparatus characterized in that the image forming apparatus collects the image. The image forming apparatus according to claim 14.
An image forming apparatus, wherein the abutting member is a rotating body, and a pressure rotating body that rolls and contacts the rotating body with the recording paper interposed therebetween. The image forming apparatus according to claim 15.
The image forming apparatus, wherein the rotating body is provided on a conveying member of the close-contact conveying means, and the pressure rotating body also serves as the rotating body of the close-contact conveying means. The image forming apparatus according to any one of claims 14 to 16,
An image forming apparatus comprising: a charging unit configured to charge the toner transferred by the transfer unit to the same polarity upstream of the unfixed toner collecting unit in the recording paper conveyance direction.

Images