WO2013014980A1

WO2013014980A1 - Image forming device and image forming method

Info

Publication number: WO2013014980A1
Application number: PCT/JP2012/059032
Authority: WO
Inventors: 裕詞中川; 村井　宏行; 松本　学; 允奥村
Original assignee: シャープ株式会社
Priority date: 2011-07-27
Filing date: 2012-04-03
Publication date: 2013-01-31
Also published as: JP2013029597A

Abstract

Even when recording paper has low surface smoothness due to the quality or shape thereof, this image forming device and image forming method perform high-quality image formation without image quality degradation by means of enabling reliable and stable transcription onto the recording paper of an image formed on an intermediary transcription member. An image forming unit (112) is provided with a transcription unit (113) which transcribes onto the recording paper a toner image formed on an image carrier, and with a fixing unit (114) which fixes a toner image on the recording paper by thermocompression of the recording paper on which the toner image is transcribed. Under prescribed conditions, a control unit (110) lets the fixing unit (114) perform thermocompression on the recording paper and smoothes the recording paper without the transcription unit (113) transcribing the toner image. Thereafter, the recording paper is conveyed to a re-transcription unit (113) by a recording paper conveyance unit (115), the toner image of the target image data is transcribed, and fixed by the fixing unit (114).

Description

Image forming apparatus and image forming method

The present invention relates to an image forming apparatus and an image forming method, and more specifically, an image forming apparatus and an image forming method for forming an image by transferring a toner image formed on an image carrier onto a recording paper and fixing it by heating. About.

In an electrostatic copying type image forming apparatus capable of forming a multicolor image, such as a color copying machine or a color printer, a toner image of each color is formed on a latent image carrier such as a photosensitive drum, and these toner images are formed. After sequentially transferring to an intermediate transfer belt to form a multicolor image, the multicolor image is transferred to a recording sheet and fixed to form an image.

There are various types and forms of recording paper on which image formation is performed. For example, embossed paper is known in which embossing is performed on the surface of the paper to give fine irregularities such as satin, cloth, and silk. In addition to intentional embossing, the surface roughness varies depending on the quality of the paper, and some of the surface irregularities are large.
Further, as a form of the recording paper, there is a form that is used by being folded in two or three, for example. For example, cardboard used for weddings, event invitations, and the like is shipped in a folded state at the papermaking stage, and it is necessary to print on such a folded sheet.

When printing on recording paper of various qualities and forms as described above, a large amount of printing processing can be performed at low cost by performing the image forming processing by the electrophotographic method as described above. However, for example, in the case of a recording paper with a rough surface roughness or large unevenness due to embossing, the intermediate transfer belt cannot sufficiently contact the entire surface of the recording paper due to the unevenness of the surface, resulting in poor transfer and image quality deterioration. There was a problem.
Also, when printing a folded paper, the surface contact between the transfer member and the recording paper is not uniform near the fold of the recording paper, and good image transfer cannot be performed near the fold. There was a problem that deterioration occurred.

Regarding the printing technology for dealing with such paper quality and form, for example, in Patent Document 1, a required item is printed with one flat certificate, and then it is automatically folded in two. A certificate issuing machine capable of discharging a certificate is shown. In this certificate issuing machine, certificate sheets on which immobile characters are printed in advance are stacked and stored in a storage box, which is taken out one by one and transferred to a printing unit for printing. After printing, the certificate paper is transferred to the folding unit, folded in half, and discharged.

Further, in Patent Document 2, when printing continuous paper, the amount of change in the shape and thickness of the folded portion of the continuous paper is easily detected, and the mountain fold and valley fold of the continuous paper folded portion are made flat. A printing device to be modified is described. This printing apparatus quantitatively recognizes the shape of the mountain folds and valley folds of the continuous paper, and before the continuous paper passes through the bottleneck between the print head and the platen roller, the paper is folded by a correction roller or a rolling plate. The part where the paper thickness of the part and the valley fold part is thick is rolled and forcibly corrected to a flat shape. This reduces the paper transport load in the bottleneck and enables stable paper feeding.

Japanese Patent Laid-Open No. 02-43071 JP 2003-2499 A

As described above, when forming the above-mentioned electrostatic copying image on recording paper having a rough surface (large irregularities), the recording paper surface is contacted uniformly and stably with a smooth intermediate transfer belt. However, it has been difficult to cause the image quality to deteriorate significantly depending on the state of the recording paper.

To deal with such problems, for example, measures are taken such as increasing the amount of toner that forms an image or increasing the transfer current to promote the transfer of a multicolor image on the intermediate transfer belt to a recording sheet. . However, when the toner adhesion amount is increased, the image such as characters is swollen on the recording paper and the image quality is deteriorated. When the transfer current is increased, retransfer due to overcurrent transfer occurs and the image quality is deteriorated. The problem arises. Therefore, it is not possible to sufficiently cope with recording sheets having various surface states simply by adjusting the image forming conditions.

Also, in the case of recording paper with a crease, printing is performed with the fold of the recording paper shipped with the crease being opened. For example, FIG. 14A shows a recording sheet folded in three, but when printing is performed, it is necessary to open the recording sheet as shown in FIG. 14B. In this case, if the user simply stretches it by hand, the crease cannot be sufficiently traced, and the crease part floats from the intermediate transfer belt, causing a transfer failure.

For example, when the crease crests having front and back ridges and valleys are brought into contact with the intermediate transfer belt, the vicinity of the crease crests floats away from the intermediate transfer belt. Further, when printing the fold valley portion, the vicinity of the fold valley portion cannot contact the intermediate transfer belt. Even if the image is formed by opening the crease in this way, image quality deterioration due to transfer failure occurs in the crease portion or in the vicinity of the crease. In particular, recording paper such as invitations for events and the like is often used with thick, thick paper, and the folds cannot be smoothed, and image quality is likely to deteriorate. For this reason, conventionally, it has been designed not to form an image near the fold.

Here, as in the invention of Patent Document 1, if the image is formed without a crease, the above problem can be solved. However, after the image is formed, a device for performing the folding in half must be installed, and the facility is complicated. Will lead to higher costs and higher costs. Further, when the user manually folds the recording paper on which the image has been formed, the operation becomes complicated and the productivity is also lowered.
Moreover, when rolling a mountain fold part and a valley fold part with a correction roller or a rolling plate and correcting it into a planar shape as in the invention of Patent Document 2, a dedicated device such as a correction roller or a rolling plate must be provided. Therefore, the equipment becomes complicated and large. In addition, such a correction roller and a rolled plate are merely in pressure contact with a mountain fold portion or a valley fold portion sandwiched from above and below, and it cannot be said that a fold-in folded portion can always be smoothed. In particular, in the case of thick cardboard used for event invitations, smoothing becomes difficult.

The present invention has been made in view of the above circumstances, and an image formed on an intermediate transfer member can be reliably and stably obtained even on a recording paper having low surface smoothness due to the quality and form of the recording paper. An object of the present invention is to provide an image forming apparatus and an image forming method capable of performing high-quality image formation without image quality deterioration by enabling transfer onto a recording sheet.

In order to solve the above problems, a first technical means of the present invention includes a recording paper transport unit that transports a recording paper, an image forming unit that forms an image on the recording paper transported by the recording paper transport unit, An image forming apparatus having a control unit that controls the recording paper transport unit and the image forming unit, wherein the image forming unit includes a transfer unit that transfers a toner image formed on an image carrier onto the recording paper; A fixing unit that fixes the toner image on the recording paper by heat-pressing the recording paper onto which the toner image has been transferred by the transfer unit, and the control unit is configured to use the toner in the transfer unit under a predetermined condition. The recording paper is controlled to be heat-pressed by the fixing unit without transferring an image.

According to a second technical means, in the first technical means, the recording paper transport unit includes a transport path for transporting the recording paper heat-pressed by the fixing unit to the transfer unit again, and the control unit includes: Under the predetermined condition, the toner image formed on the image carrier by the transfer unit is transported again to the transfer unit after the recording paper is heat-pressed by the fixing unit without transferring the toner image at the transfer unit. Is transferred onto the recording paper.

A third technical means includes an operation unit that receives a user's operation input in the first or second technical means, and the control unit has a predetermined condition according to a predetermined operation input to the operation unit as the predetermined condition. When the mode is set, the recording paper is heat-pressed by the fixing unit without transferring the toner image by the transfer unit.

A fourth technical means includes an image input unit for inputting image data to be image-formed from an external device in the first or second technical means, and the control unit sets the image input unit as the predetermined condition. When the image data input from the printer includes instruction information for image formation in a predetermined mode, the recording paper is heated and pressed by the fixing unit without transferring the toner image by the transfer unit. It is characterized by.

A fifth technical means is the intermediate transfer according to any one of the first to fourth technical means, wherein the transfer unit transfers a plurality of image carriers and the toner images formed on the plurality of image carriers. A belt, a transfer roller for transferring the toner image transferred to the intermediate transfer belt onto the recording paper, and a drive mechanism unit for contacting or separating the image carrier and the intermediate transfer belt, The drive mechanism section separates the image carrier and the intermediate transfer belt under the predetermined condition.

According to a sixth technical means, in the technical means according to any one of the first to fifth aspects, the control unit determines the transport speed of the recording paper that passes through the fixing unit under the predetermined condition at the transfer unit. It is characterized in that it is lower than the conveying speed when the toner image is transferred onto the recording paper.

According to a seventh technical means, in the technical means according to any one of the first to sixth aspects, the controller controls the heating temperature of the fixing unit under the predetermined condition, and the toner image is transferred onto the recording paper by the transfer unit. It is characterized in that the temperature is higher than the heating temperature of the fixing portion when transferring.

An eighth technical means is an image having a transfer section that transfers a toner image formed on an image carrier onto the recording paper, and a fixing section that fixes the toner image transferred by the transfer section by thermocompression bonding. An image forming method executed by a forming apparatus, the step of heat-pressing the recording paper in the fixing unit without transferring the toner image in the transfer unit, and the heat-pressed recording paper in the transfer unit A transfer step for conveying and transferring the toner image onto the recording paper; and a fixing step for fixing the toner image transferred in the transfer step onto the recording paper with the fixing unit. An image forming method.

According to the present invention, even if the recording paper has low surface smoothness due to the quality and form of the recording paper, the image formed on the intermediate transfer member can be reliably and stably transferred to the recording paper. It is possible to provide an image forming apparatus and an image forming method capable of performing high-quality image formation without image quality deterioration.

1 is a block diagram illustrating a main configuration of an image forming apparatus according to the present invention. 1 is a diagram illustrating an embodiment in which an image forming apparatus according to the present invention is configured as a multifunction peripheral. FIG. 4 is a diagram illustrating a configuration and an operation of a driving mechanism unit of an intermediate transfer belt with respect to a photosensitive drum. FIG. 10 is another diagram illustrating the configuration and operation of the driving mechanism unit of the intermediate transfer belt with respect to the photosensitive drum. FIG. 10 is still another diagram illustrating the configuration and operation of the drive mechanism unit of the intermediate transfer belt with respect to the photosensitive drum. 6 is a flowchart for explaining an example of image forming processing in the image forming apparatus according to the present invention. 6 is a diagram illustrating an example of an operation screen of a printer driver operating on an information processing apparatus such as a PC. FIG. 3 is a diagram illustrating an example of an operation panel of the image forming apparatus. FIG. It is a figure which shows the example of a display screen of the operation display part of an operation panel. It is a figure which shows the example of a special function setting screen. It is a figure which shows the other example of the setting screen of a special function. FIG. 6 is a diagram illustrating a state in which a setting button for recording paper smoothing printing is highlighted. It is a figure which shows the example of an operation screen which shows the state in which recording paper smoothing printing was set. It is a figure for demonstrating the state of the recording paper with a crease | fold.

FIG. 1 is a block diagram showing a main configuration of an image forming apparatus according to the present invention. The image forming apparatus 100 forms image data on recording paper that is transmitted from the outside or read by an image reading unit such as a scanner, and is a monochromatic or multicolor toner on a latent image carrier such as a photosensitive drum. An electrostatic copying type image forming apparatus that forms an image, sequentially transfers these toner images to an intermediate transfer belt to form an image, transfers the image to a recording sheet, and fixes the image to form an image. .

The control unit 110 controls each function of the image forming apparatus, and is realized by a microcomputer having a CPU, a ROM, a RAM, and the like inside.
The operation unit 111 receives an operation input by the user and outputs the operation input to the control unit 110. The display unit 116 displays an operation screen and various types of information. The operation unit 111 and the display unit 116 can constitute a touch panel that can perform an input operation on the operation screen.
The image input unit 117 receives image data from image data input from an externally connected information processing apparatus or the like, or a scanner unit (image reading unit) (not shown) that can be provided in the image forming apparatus, or a portable recording medium. The image data output from the recording medium reading unit to be read is input.

The image forming unit 112 performs image formation (printing) of image data on recording paper according to the control of the control unit 110, and includes a transfer unit 113 and a fixing unit 114. The transfer unit 113 forms a toner image based on image data on a plurality of image carriers such as a photosensitive drum, and transfers the formed toner image onto an intermediate transfer belt. Then, the toner image on the intermediate transfer belt is transferred onto the conveyed recording paper. The fixing unit heats and presses the recording paper onto which the toner image is transferred by a heat roller and a pressure roller, and fixes the toner image on the recording paper to form an image.

The recording paper transport unit 115 controls the transport of the recording paper on which image formation is performed. The recording paper is placed on a paper feed tray (not shown) and conveyed from the predetermined conveying path to the image forming unit 112 to form an image. As the conveyance path, the recording sheet fed from the sheet feeding tray sequentially passes through the transfer unit 113 and the fixing unit 114 of the image forming unit 112 and is discharged, and the recording sheet passes through the fixing unit 114. A conveyance path for double-sided printing is provided which is turned upside down and sent to the transfer unit 114 again. By using the double-sided conveyance path, it is possible to cause the transfer unit 113 to form an image while the recording paper once heated and pressed by the fixing unit 114 is reversed. The recording paper transport unit 115 switches the transport path and changes the transport speed according to the control of the control unit 110.

In the embodiment according to the present invention, using the above configuration, the fixing unit 114 does not perform image formation in the transfer unit 113 on a recording sheet having a rough surface such as a creased recording sheet or an embossed sheet. Then, the recording paper is conveyed, and the fixing section 114 heats and presses the recording paper to improve the smoothness. Thereafter, the recording paper is sent to the transfer unit 113 using the double-sided conveyance path, and image formation of target image data is performed. Thereafter, a fixing process is performed by the fixing unit 114 and the sheet is discharged. However, if necessary, double-sided printing can be performed using the double-sided conveyance path again. Further, it is possible to set the smoothness improving process in the fixing unit 114 to be executed a plurality of times according to the difference in the thickness of the paper, the degree of embossing, and the like by user operation. In this case, after the recording paper is heated and pressed by the fixing unit 114, the recording paper is sent again to the fixing unit 114 using the double-sided conveyance path, and the heating and pressing processing is repeated, so that the smoothness according to the state of the recording paper is obtained. The degree of improvement process can be appropriately executed. Further, in the heating / crimping process in the fixing unit 114, the conveyance speed of the recording paper can be lowered or the heating temperature can be increased as compared with the normal image formation.

By such an operation, even if the recording paper has a rough surface, such as a creased recording paper or an embossed paper, image formation is performed after smoothing the recording paper, thereby ensuring reliable and stable image data. As a result, the image can be transferred to a recording sheet and a high-quality image can be obtained.
Since the transfer unit 113, the fixing unit 114, the recording paper transport unit 115, and the like of the image forming unit 112 are normally configured in a multi-function device as a standard, the multi-function device can perform the above processing only by changing firmware. The embodiment according to the present invention can be easily implemented without increasing costs.

FIG. 2 is a diagram showing an embodiment in which the image forming apparatus according to the present invention is configured as a multifunction peripheral, and shows an example of the image forming apparatus configured as a multifunction peripheral having a scanner function.
The image forming apparatus 100 forms an image on recording paper, which is image data transmitted from the outside or read by a scanner (image reading means), and includes an apparatus main body 130 and an automatic document processing apparatus 120.

The apparatus main body 130 includes an exposure unit 1, a developing device 2, a photosensitive drum 3, a cleaner unit 4, a charger 5, an intermediate transfer belt unit 6, a fixing unit 7, a paper feed cassette 81, a paper discharge tray 91, and the like.
A document placing table 92 made of transparent glass is provided on the upper portion of the apparatus main body 130, and an automatic document processing device 120 that automatically conveys the document to the document placing table 92 is attached on the upper side. The automatic document processing device 120 is configured to be rotatable in the direction of arrow M, and the document can be placed manually by opening the document table 92.

The apparatus main body 130 has an image reading means 90 accommodated in the housing. The image reading means 90 is a reduction optical system image reading means composed of a light source unit 93 that holds the light source and the first mirror, a mirror unit 94 that holds the second and third mirrors, and a lens and the CCD 95. . In addition, the apparatus main body 130 is provided with an operation panel (not shown) so that a user can input an operation. The operation panel corresponds to the operation unit 111 and the display unit 116 in FIG. Further, the apparatus main body 130 includes means for inputting image data from an externally connected apparatus, or means for reading image data from a portable recording medium (none of which is shown).

Image data handled in the image forming apparatus 100 corresponds to, for example, four color images of black (K), cyan (C), magenta (M), and yellow (Y). Accordingly, four each of the developing device 2, the photosensitive drum (image carrier) 3, the charger 5, and the cleaner unit 4 are provided so as to form four types of latent images corresponding to the respective colors. An image station is configured.

The charger 5 is a charging means for uniformly charging the surface of the photosensitive drum 3 to a predetermined potential. In addition to the charger type as shown in FIG. 2, a contact type roller type or brush type charger may be used. Sometimes used.
The exposure unit 1 is configured as a laser scanning unit (LSU) provided with a laser emitting portion, a reflection mirror, and the like. The exposure unit 1 includes a polygon mirror that scans a laser beam and optical elements such as a lens and a mirror for guiding the laser beam reflected by the polygon mirror to the photosensitive drum 3. In addition, as the exposure unit 1, for example, a method using an EL or LED writing head in which light emitting elements are arranged in an array can be employed.

The exposure unit 1 has a function of forming an electrostatic latent image corresponding to the image data on the surface thereof by exposing the charged photosensitive drum 3 according to the input image data. The developing unit 2 visualizes the electrostatic latent images formed on the respective photosensitive drums 3 with toners of four colors (Y, M, C, K). The cleaner unit 4 removes and collects toner remaining on the surface of the photosensitive drum 3 after development and image transfer.

The intermediate transfer belt unit 6 disposed above the photosensitive drum 3 includes an intermediate transfer belt 61, an intermediate transfer belt driving roller 62, an intermediate transfer belt driven roller 63, an intermediate transfer roller 64, and an intermediate transfer belt cleaning unit 65. I have. Four intermediate transfer rollers 64 are provided corresponding to each color of Y, M, C, and K.
The intermediate transfer belt driving roller 62, the intermediate transfer belt driven roller 63, and the intermediate transfer roller 64 are driven to rotate while the intermediate transfer belt 61 is stretched. Each intermediate transfer roller 64 provides a transfer bias for transferring the toner image on the photosensitive drum 3 onto the intermediate transfer belt 61.

The intermediate transfer belt 61 is provided so as to be in contact with each photoconductor drum 3, and the toner images of the respective colors formed on the photoconductor drum 3 are sequentially transferred to the intermediate transfer belt 61 and transferred. Then, a color toner image (multicolor toner image) is formed on the intermediate transfer belt 61. The intermediate transfer belt 61 is formed endlessly using, for example, a film having a thickness of about 100 μm to 150 μm.

Transfer of the toner image from the photosensitive drum 3 to the intermediate transfer belt 61 is performed by an intermediate transfer roller 64 in contact with the back side of the intermediate transfer belt 61. A high voltage transfer bias (a high voltage having a polarity (+) opposite to the toner charging polarity (−)) is applied to the intermediate transfer roller 64 in order to transfer the toner image. The intermediate transfer roller 64 is a roller whose base is a metal (for example, stainless steel) shaft having a diameter of 8 to 10 mm and whose surface is covered with a conductive elastic material (for example, EPDM, urethane foam, or the like). With this conductive elastic material, a high voltage can be uniformly applied to the intermediate transfer belt 61. In this configuration example, a roller shape is used as the transfer electrode, but a brush or the like can also be used.

As described above, the electrostatic images visualized according to the hues on the photosensitive drums 3 are stacked on the intermediate transfer belt 61. The stacked electrostatic images are transferred onto the recording sheet by the rotation of the intermediate transfer belt 61 by a transfer roller 10 which is a secondary transfer mechanism unit disposed at a contact position between the sheet and the intermediate transfer belt 61 described later. The The secondary transfer mechanism is not limited to a transfer roller, and a corona charger or a transfer belt can also be used.

At this time, the intermediate transfer belt 61 and the transfer roller 10 are pressed against each other at a predetermined nip, and a voltage for transferring the toner to the sheet is applied to the transfer roller 10 (the polarity opposite to the toner charging polarity (−)). (+) High voltage). Further, in order to obtain the nip constantly, the transfer roller 10 uses either the transfer roller 10 or the intermediate transfer belt drive roller 62 as a hard material (metal or the like) and the other as a soft material (elasticity such as an elastic roller). Rubber roller, foaming resin roller, etc.).

Further, as described above, the toner adhered to the intermediate transfer belt 61 by contacting the photosensitive drum 3 or the toner remaining on the intermediate transfer belt 61 without being transferred to the recording paper by the transfer roller 10 is used in the next step. Therefore, the intermediate transfer belt cleaning unit 65 is configured to remove and collect the toner. The intermediate transfer belt cleaning unit 65 includes a cleaning blade as a cleaning member that comes into contact with the intermediate transfer belt 61. The intermediate transfer belt 61 that comes into contact with the cleaning blade is supported by an intermediate transfer belt driven roller 63 from the back side. ing.

1 is constituted by the intermediate transfer belt unit 6 and the transfer roller 10 described above. A driving mechanism (not shown) for contacting or separating the photosensitive drum 3 and the intermediate transfer belt 61 is provided. The configuration and operation of this drive mechanism will be described later.

The paper feed cassette 81 is a tray for storing recording paper (sheets) used for image formation, and is provided below the exposure unit 1 of the apparatus main body 130. In addition, recording paper used for image formation can also be placed in the manual paper feed cassette 82. A paper discharge tray 91 provided above the apparatus main body 110 is a tray for collecting printed recording sheets face down.

In addition, the apparatus main body 110 includes a substantially vertical sheet conveyance path S1 for feeding the recording sheets of the sheet feeding cassette 81 and the manual sheet feeding cassette 82 to the sheet discharge tray 91 via the transfer roller 10 and the fixing unit 7. Is provided. In the vicinity of the sheet conveying path S1 from the sheet feeding cassette 81 or the manual sheet feeding cassette 82 to the sheet discharge tray 91,

pickup rollers

11a and 11b, a plurality of conveying rollers 12a to 12d, a registration roller 13, a transfer roller 10, and a fixing unit. 7 etc. are arranged.

The transport rollers 12a to 12d are small rollers for promoting and assisting the transport of the recording paper, and a plurality of the transport rollers 12a to 12d are provided along the paper transport path S1. The pickup roller 11 a is provided near the end of the paper feed cassette 81, picks up recording paper from the paper feed cassette 81 one by one, and supplies it to the paper transport path S. Similarly, the pickup roller 11b is provided near the end of the manual paper feed cassette 82, picks up recording paper from the manual paper feed cassette 82 one by one, and supplies it to the paper transport path S1.

Further, the registration roller 13 temporarily holds the recording paper conveyed through the paper conveyance path S1. The recording paper is transported to the transfer roller 10 at the timing when the leading edge of the toner image on the photosensitive drum 3 is aligned with the leading edge of the recording paper.

The fixing unit 7 corresponds to the fixing unit 114 in FIG. 1 and includes a heat roller 71 and a pressure roller 72. The heat roller 71 and the pressure roller 72 are configured to rotate with the recording paper interposed therebetween. The heat roller 71 is set so as to reach a predetermined fixing temperature by a control means based on a signal from a temperature detector (not shown). It has the function of fusing, mixing, and pressing the multicolor toner image transferred to the paper, and thermally fixing the recording paper. An external heating belt 73 for heating the heat roller 71 from the outside is provided.

Next, the recording paper conveyance path will be described in more detail. As described above, the image forming apparatus 100 is provided with the paper feed cassette 81 and the manual paper feed cassette 82 that store recording paper in advance. In order to feed the recording paper from these

paper feeding cassettes

81 and 82,

pickup rollers

11a and 11b are respectively arranged to guide the recording paper one by one to the transport path S1.

The recording paper conveyed from each of the

paper feed cassettes

81 and 82 is conveyed to the registration roller 13 by the conveyance roller 12a in the paper conveyance path S1, and the timing at which the leading edge of the recording paper and the leading edge of the image information on the intermediate transfer belt 61 are aligned. Then, the toner image is conveyed to the transfer roller 10 and the toner image is transferred onto the recording paper. Thereafter, the recording paper passes through the fixing unit 7, whereby the unfixed toner on the recording paper is melted and fixed by heat, and is then discharged onto the paper discharge tray 91 through the conveying roller 12 b disposed thereafter.

The above-mentioned transport path is for a single-sided printing request for recording paper. On the other hand, for a double-sided printing request, the single-sided printing is completed and the recording paper after passing through the fixing unit 7 as described above. When the end is gripped by the final transport roller 12b, the transport roller 12b rotates in reverse to guide the recording paper to the transport path S2 in which the transport rollers 12c and 12d are arranged. Then, the conveyance path S2 joins the conveyance path S1, and the recording paper is conveyed from the registration roller 13 to the transfer roller 10. At this time, since the front and back sides of the recording paper are reversed at the stage of joining from the conveyance path S2 to S1, the transfer roller 10 performs printing on the back side of the recording paper. Then, the recording paper printed on the back surface is fixed by the fixing unit 7 and discharged to the paper discharge tray 91.

The conveyance path S2 used for the above-described double-sided printing is used when printing on a recording paper having a rough surface such as a creased recording paper or an embossed paper. In this case, the recording paper fed from the

paper feed cassettes

81 and 82 is sent to the fixing unit 7 without image formation at the transfer portion of the intermediate transfer belt unit 6 and the transfer roller 10, and is heated / heated by the fixing unit 7. A process of pressure bonding and smoothing is performed.

Then, the smoothed recording paper is conveyed again from the conveyance path S1 to the transfer unit using the conveyance path S2 for double-sided printing. Here, the transfer unit transfers the toner image of the target image data onto the recording paper. Since the recording paper is already smoothed by the fixing unit 7, the transfer from the intermediate transfer belt 61 can be reliably performed. The toner image transferred to the recording paper is fixed by the fixing unit 7 and then discharged. At this time, when performing double-sided printing, the recording paper is again conveyed to the conveyance path S2 for double-sided printing, and image formation is performed on the surface opposite to the surface on which image formation was performed at the first time. it can.

Further, the above smoothing treatment can be appropriately performed a plurality of times according to the difference in the thickness of the paper and the degree of embossing. Here, the number of times the smoothing process is executed can be set in accordance with a user operation. In this case, the recording unit is heated and pressed by the fixing unit 7 to perform the smoothing process, and then the recording sheet is sent again to the fixing unit 7 using the conveyance path S2 for double-sided printing to perform the heating and pressing process. . This operation can be executed a plurality of times further according to user settings. When the predetermined number of smoothing processes are completed, the conveyance path S2 for double-sided printing is used again, and the toner image formed on the intermediate transfer belt 61 is transferred to form an image. By such processing, the user can execute smoothness improvement processing according to the thickness of the creased paper and the degree of surface roughness due to embossing or the like.

As described above, in the embodiment of the image forming apparatus according to the present invention, when image formation is performed using recording paper with a rough surface or recording paper with a crease, the toner image is transferred and fixed onto the recording paper. Before performing, the fixing unit 7 is used to perform a smoothing process in which the recording paper is pressurized while being heated. Thereby, the recording paper having a rough surface or the recording paper with a crease can be smoothed, and the recording paper can be reliably brought into contact with the intermediate transfer belt 61 to obtain a high-quality transfer image. In addition, since the moisture of the recording paper is removed by heating and the resistance of the recording paper is increased, an effect of improving toner transferability can be obtained.

In order to perform the above operation, the embodiment according to the present invention is configured to be able to take any one of (A) a color image formation mode, (B) a monochrome image formation mode, and (C) a non-image formation mode. . In the case of heating and pressurizing as a smoothing process without forming an image on the recording paper, the non-image forming mode of (C) is set. In the non-image forming mode, the running position of the intermediate transfer belt 61 is moved to separate the intermediate transfer belt 61 from all the photosensitive drums 3. This prevents the residual toner (so-called fog toner) existing on the photosensitive drum 3 from adhering to the recording paper.

Further, in the color image forming mode, control is performed so that the intermediate transfer belt 61 contacts all the photosensitive drums 3 for Y, M, C, and K. In the monochrome image forming mode, control is performed so that the intermediate transfer belt 61 contacts only the K photosensitive drum 3. In this way, control is performed so that the intermediate transfer belt 61 contacts only the photosensitive drum 3 used for image formation according to color or monochrome.

A configuration for switching the above modes will be described. The following configuration specifically shows the configuration of the drive mechanism unit of the present invention.
3 to 5 are diagrams for explaining the configuration and operation of the drive mechanism unit of the intermediate transfer belt with respect to the photosensitive drum. In the following description and each drawing, when it is necessary to distinguish between the photosensitive drum 3 and the intermediate transfer roller 64 corresponding to each color of Y, M, C, and K, each photosensitive drum 3 and each intermediate drum. The transfer roller 64 is identified by adding Y, M, C, K indicating each color after the reference numeral.

FIG. 3 is a diagram illustrating a state of a color image forming mode in which image formation is performed using all the photosensitive drums. Each of the

intermediate transfer rollers

64Y, 64M, and 64C arranged to face the Y, M, and C

photoconductive drums

3Y, 3M, and 3C is one arm of a transfer roller arm 31 formed in a substantially L shape. It is rotatably supported at the tip of 31a (hereinafter referred to as “horizontal armband”).
The transfer roller arm 31 has an L-shaped bent portion 31b supported and fixed to an apparatus frame (not shown) so as to be rotatable, and the other arm rod (hereinafter referred to as “vertical arm rod”) 31c of the transfer roller arm 31. The distal end portion is rotatably supported by the first slide rod 35. The first slide rod 35 is disposed so as to be capable of reciprocating in the horizontal direction.

3 is in contact with the cam surface of a first eccentric cam 37 that is rotatably held by a cam shaft 36 on a device frame (not shown). Further, the right end portion of the first slide rod 35 is secured by a first spring 32 in which one end portion 32a is locked and fixed to a device frame (not shown) and the other end portion 32b is locked and fixed to the first slide rod 35. 35 a is urged so as to be always in pressure contact with the cam surface of the first eccentric cam 37.

On the other hand, the intermediate transfer roller 64K arranged to face the photosensitive drum 3K rotates to the tip of one arm rod (hereinafter referred to as “lateral arm rod”) 33a of the L-shaped transfer roller arm 33. Supported as possible. The transfer roller arm 33 has an L-shaped bent portion 33b rotatably supported on an apparatus frame (not shown), and a tip end portion of the other arm rod (hereinafter referred to as “vertical arm rod”) 33c of the transfer roller arm 33. Is rotatably supported by a second slide rod 38 that is disposed so as to be reciprocally movable in the horizontal direction.

The backup roller 66 is rotatably supported at the tip of one arm rod (hereinafter referred to as “lateral arm rod”) 43a of the backup roller arm 43 formed in a substantially L shape. The backup roller arm 43 has an L-shaped bent portion 43b supported and fixed to an apparatus frame (not shown) so as to be rotatable. The other arm rod of the backup roller arm 43 (hereinafter referred to as “vertical arm rod”). A tip end portion of 43c is rotatably supported by the second slide rod 38.

3 is in contact with the cam surface of a second eccentric cam 39 that is rotatably held by a cam shaft 36 on a device frame (not shown). Further, the second slide rod 38 has a second end 34 a locked and fixed to a device frame (not shown), and the other end 34 b is locked and fixed to the second slide rod 38 by the second spring 34. The left end 38 a of the slide rod 38 is urged so as to be always in pressure contact with the cam surface of the second eccentric cam 39.

Further, an optical sensor 51 is disposed at a position facing the backup roller 66 through the intermediate transfer belt 61. The backup roller 66 is provided in front of the optical sensor 51, and the intermediate transfer belt 61 can be flattened to accurately detect the reflected light (density) of the reference toner.

A tension roller 67 for applying a predetermined tension to the intermediate transfer belt 61 is rotatably supported by the tip 45a of the tension roller arm 45. The lower end portion 45b of the tension roller arm 45 is rotatably supported by a device frame (not shown). Although not shown, the tension roller arm 45 is biased so as to always apply a predetermined tension to the intermediate transfer belt 61 by biasing means such as a coil spring.
Further, the first slide rod 35 is provided with a protrusion 35d, and a detection switch 48 is attached and fixed to a device frame (not shown) in the vicinity of the protrusion 35d. It is detected by the detection switch 48 whether or not the first slide rod 35 is sliding.

In the arrangement as described above, the horizontal arm rods 31a of the

transfer roller arms

31Y, 31M, 31C corresponding to Y, M, and C, the horizontal arm rods 33a of the transfer roller arm 33K corresponding to K, and the backup roller arm. 43 horizontal arm rods 43a are arranged in opposite directions.

By the rotation control of the first eccentric cam 37 and the second eccentric cam 39, the first slide rod 35 can be moved in the right direction X1 from the position shown in FIG. 3 as shown in FIG. At this time, the

transfer roller arms

31Y, 31M, and 31C rotate in the right direction R1 around the rotation fulcrum of the bent portions 31b, and the horizontal arm rods 31a move upward, and the

intermediate transfer rollers

64Y, 64M. , 64C are separated from the intermediate transfer belt 61. As a result, the intermediate transfer belt 61 is separated from the

photosensitive drums

3Y, 3M, 3C. At this time, the detection switch 48 changes from the OFF state shown in FIG. 3 to the ON state shown in FIG. FIG. 4 shows a monochrome image forming mode in which image formation is performed only on the K photosensitive drum 3K.

On the other hand, when the second slide rod 38 moves from the position shown in FIG. 4 in the left direction X2 as shown in FIG. 5 by the rotation control of the first eccentric cam 37 and the second eccentric cam 39, the transfer roller arm 33K and The backup roller arm 43 rotates in the left direction R2 around the rotation fulcrum of each

bent portion

33b, 43b. At this time, the

horizontal arm rods

33a and 43a move upward, and the intermediate transfer roller 64K and the backup roller 66 are separated from the intermediate transfer belt 61. As a result, the intermediate transfer belt 61 is separated from the photosensitive drum 3K and the optical sensor 51. become.
In this state, a non-image forming mode in which the intermediate transfer belt is separated from all the

photosensitive drums

3Y, 3M, 3C, and 3K is set. In the image forming apparatus, when heating / pressurizing processing is performed on a recording sheet having a rough surface or a creased recording sheet, the state is shifted to the non-image forming mode.

With the above configuration, the control unit (not shown) of the image forming apparatus changes the state of the intermediate transfer belt 61 to, for example, a color image forming mode, a monochrome image forming mode, or a non-image forming mode. Take control. The mode change can be executed based on a mode condition set based on a user operation on the operation panel, for example. When image data is input from an external device such as a PC (personal computer) or a recording medium, if the image data includes information indicating a mode, the mode is changed according to the information. For example, if the information for instructing the recording paper smoothing process is included in the image data, the control unit of the image forming apparatus shifts to the non-image forming mode and performs the recording paper smoothing process.

Further, the control unit determines each of the above modes based on the output from the optical sensor 51 and the detection signal from the detection switch 48. For example, if the detection switch 48 is OFF and the optical sensor 51 is ON (with reflected light), it is determined that the color image formation mode is in the state shown in FIG. 2, and the detection switch 48 is ON and the optical sensor 51 is ON (reflected light). 4), it is determined that the monochrome image forming mode is in the state shown in FIG. 4. If the detection switch 48 is ON and the optical sensor 51 is OFF (no reflected light), the non-image forming mode in the state shown in FIG. It is determined that An eccentric cam drive source (motor) is connected to the controller, and the first eccentric cam 37 and the first eccentric cam 37 are controlled by detecting the state of the intermediate transfer belt 61 and controlling the eccentric cam drive source. 2 The operation mode can be set by controlling the rotation of the eccentric cam 39.

FIG. 6 is a flowchart for explaining an example of image forming processing in the image forming apparatus according to the present invention. As the image forming apparatus, a multifunction machine as shown in FIG. 2 can be applied. In this case, the image data to be formed by the image forming apparatus can be image data read by the image reading means of the multifunction peripheral, image data input from an external device such as a PC, or the like. In the following example, an example of processing when image data edited by an external PC is image formed (printed) by the image forming apparatus will be described.

First, an application for image editing operates on an external PC, and image data for printing (image formation) is edited by the user (step S1). When editing is completed (step S2-Yes), the user determines whether or not the edited image is to be printed by the image forming apparatus (step S3). When printing is not performed, the edited image data is saved on the PC, the image editing application is closed, and the process ends.

When printing in step S3, the user operates the PC to perform print settings (setting of image forming conditions) (step S4). In the print setting, for example, general print settings such as recording paper size, single-sided printing, double-sided printing, and margin setting are performed. Then, when the recording paper is, for example, a recording paper with a crease such as an invitation or a recording paper with a rough surface such as an embossed paper, the recording paper is smoothed (step S5).

When the user operates the PC to execute printing (step S6—Yes), the edited image data is transmitted as image data as print data. At this time, if execution of the recording paper smoothing process is set, the instruction information is also included in the image data and transmitted. The image forming apparatus that has received the image data checks whether or not the recording paper smoothing process set by the user has been executed (step S7). When the recording paper smoothing process is executed, the image forming apparatus shifts to the non-image forming mode and separates the intermediate transfer belt from all the photosensitive drums (step S8). This prevents the residual toner on the surface of the photosensitive drum from adhering to the recording paper.

Next, the image forming apparatus sets a charging bias for the photosensitive drum, a charging bias for the intermediate transfer belt, and a charging bias for the transfer roller (step S9).
When performing the smoothing process, the toner image is not transferred to the recording paper, but is passed through the transfer roller 10 and sent to the fixing unit 7. At this time, the following bias application is performed so that the toner does not adhere to the recording paper.

For example, when a negative polarity toner is used, the photosensitive drum 3 is separated from the intermediate transfer belt 61, so that a cleaning bias is applied or no bias is applied. By applying a weak positive bias of about several hundred volts (+100 to 200) to the intermediate transfer belt 61, the negative polarity toner remaining on the intermediate transfer belt 61 can be sucked. Thereby, residual toner can be prevented from adhering to the recording paper.
Further, by applying a weak negative bias of about several hundred volts (−100 to 200) to the transfer roller 10, negative polarity toner is repelled, so that the transfer roller 10 and the transfer roller 10 do not adhere to the recording paper. A nip portion with the intermediate transfer belt 61 can be passed.

When the pre-processing necessary for printing such as bias setting and application is performed in step S9, the image forming apparatus determines whether all pre-processing such as temperature setting of the fixing unit 7 is completed and printing is possible. Is confirmed (step S10).
If printing is possible, the recording paper is smoothed (step S12). Here, without writing the image data onto the photosensitive drum 3 by the exposure unit 1, the recording paper is fed and passed through the nip portion between the transfer roller 10 and the intermediate transfer belt 61 to reach the fixing unit 7. Let

In the fixing unit 7, the recording paper is heated and pressed by the heat roller 71 and the pressure roller 72, and smoothing processing such as erasing the crease marks or reducing the surface roughness is performed. In this case, the recording paper can be smoothed more effectively by reducing the conveyance speed of the recording paper or increasing the set temperature of the fixing unit 7 during the smoothing process.

Specifically, when the smoothing process is performed, the conveyance speed of the recording paper that passes through the fixing unit 7 is made lower than the conveyance speed when the toner image is transferred onto the recording paper and image formation is performed. . Further, the heating temperature of the fixing unit 7 is set higher than the heating temperature of the fixing unit 7 when the toner image is transferred onto the recording paper to form an image. Thereby, the temperature of the heating / compression treatment for the recording paper can be increased, the processing time can be lengthened, and the smoothing effect can be further enhanced. Either one of the decrease in the conveyance speed and the increase in the heating temperature may be performed.

In the image forming apparatus, after the smoothing process, the image data is printed. Here, first, the intermediate transfer belt 61 separated from the photosensitive drum 3 is brought into contact with the photosensitive drum 3 again (step S13). Here, the intermediate transfer belt 61 is brought into contact with the required photosensitive drum 3 in accordance with the color image forming mode or the monochrome image forming mode.

Then, one-sided printing or two-sided printing is performed on the recording paper according to the print setting (step S14). Here, when the trailing edge of the recording paper that has passed through the fixing unit 7 by the smoothing process in step S12 reaches the conveying roller 12b behind the fixing unit 7, the conveying roller 12b is rotated in the reverse direction. Thereby, the recording paper is conveyed to the double-sided conveying path S2 where the conveying rollers 12c and 12d are arranged by the switchback in which the front and back of the recording paper are reversed. Then, the recording paper is fed again from the registration roller 13 between the transfer roller 10 and the intermediate transfer belt 61. In the image forming apparatus 100, after the smoothing process is completed, an operation of bringing the intermediate transfer belt 61 into contact with the photosensitive drum 3 is performed while the recording sheet is being conveyed on the duplex conveying path S <b> 2. Then, when the recording paper conveyed through the double-sided conveyance path S2 passes between the transfer roller 10 and the intermediate transfer belt 61 again, the toner image is transferred onto the recording paper.

Further, in the above processing, when the recording paper to be smoothed has a crease, when the recording paper is conveyed so that the ridge of the recording paper contacts the heat roller 71 side of the fixing unit 7, The fold can be smoothed more effectively. In this case, the creased recording paper is opened by the user and placed on the manual paper feed cassette 82. At this time, the recording paper is placed so that the peak of the fold of the recording paper faces downward and the valley of the fold faces upward. As a result, the crest side of the recording paper conveyed to the fixing unit 7 comes into contact with the heat roller 71, and the creases are effectively smoothed.

When the trailing edge of the recording sheet reaches the conveying roller 12b, the conveying roller 12b is rotated in the reverse direction. After the recording sheet is conveyed to the double-sided conveying path S2 by switchback, the transfer roller 10 and the intermediate transfer belt 54 Print through the space. At this time, since the front and back sides of the recording paper are reversed by the switchback, when printing is performed, printing is performed on the valley side surface of the creased recording paper.

Further, when the recording paper smoothing process is not performed in step S7, since the printing process is a normal printing process, the image forming apparatus performs printing according to image data to be printed, temperature, humidity, deterioration state of each device, and the like. A bias for normal printing is set (step S11). Then, the process proceeds to step S14, and single-sided printing or double-sided printing is performed on the recording paper according to the print setting.

When printing on the recording paper is performed in this manner, the presence / absence of another printing is confirmed, and if printing is completed (Yes in step S15), the process is terminated. If printing has not ended (step S15-No), the process returns to step S7 to determine whether or not the next recording paper is smoothed, and the smoothing process and the printing process are continued.

FIG. 7 is a diagram illustrating an example of an operation screen of a printer driver operating on an information processing apparatus such as a PC. An example of a print setting screen of a printer driver for causing an image forming apparatus connected to the information processing apparatus to perform printing It is shown.
On the print setting screen 200, as with a normal printer driver, a number-of-prints setting unit 201, a double-sided print setting unit 202, an N-Up (multiple image aggregated print) setting unit 203, staple and punch settings, etc. A finishing setting unit 204, a user setting unit 205, a job management unit 206, and the like are set. In addition to these setting items, a recording paper smoothing print setting unit 208 according to the present invention is provided.

The user can create a print image with an image editing application of the information processing apparatus, for example, and open a printer driver operation screen shown in FIG. At this time, the recording paper smoothing process can be set by checking the check box of the recording paper smoothing print setting unit 208. When the user presses an OK button 207, image data for printing is transmitted to the image forming apparatus and printing is executed. At this time, the image forming apparatus is instructed to execute the recording paper smoothing process. In the image forming apparatus, according to this instruction, the recording unit smoothes the recording paper by the fixing unit 7 and then prints the image data.

FIG. 8 is a diagram illustrating an example of an operation panel of the image forming apparatus. The image forming apparatus 100 includes an operation panel 300 that constitutes an operation unit and a display unit for performing user operations. The operation panel 300 is provided with a start key 301, an all cancel key 302, a clear key 303, and a numeric keypad 304. Further, a hard key group for setting functions such as document filing, faxing, copying, and confirming the job status. 305 is provided, and user operations are possible as appropriate. The operation panel 300 is provided with an operation display unit 306 configured as a touch panel.

FIG. 9 is a diagram showing a display screen example of the operation display section of the operation panel. The operation display unit 306 can display an operation screen 310 for performing image forming processing. An operation screen 310 in FIG. 9 is an operation screen for setting a copy function. Setting

buttons

312 and 313 regarding finishing such as duplex copying and finishing, setting

buttons

314 and 315 regarding data storage such as filing and automatic temporary storage, A status display unit 316 that indicates the status of the paper feed tray, a document setting button 317 for performing various document settings, and the like, and a special function setting button 311 for setting special functions of the image forming apparatus are displayed.

When the user operates the special function setting button 311 on the operation screen 310 in FIG. 9, a special function setting screen 320 shown in FIG. 10 is displayed. On the special function setting screen 320, buttons for setting various special function items are set. In this example, the special function setting screen is divided into a plurality of screens because the number of setting items is large. Here, when the user operates the downward arrow 321, the next setting screen 330 of the special function as shown in FIG. 11 is displayed.

11 is provided with a setting button 331 for recording paper smoothing printing. When the user operates the setting button 331, the setting button 331 is highlighted as shown in FIG. 12 to clearly indicate that the recording paper smoothing print setting is being selected. By pressing the OK button 332 in this state, the special function setting is confirmed and the operation screen 310 of FIG. 13 is displayed. At this time, the number of times the fixing unit 7 is allowed to pass may be set using the numeric keypad 304 shown in FIG. As a result, a plurality of smoothing processes using the fixing unit 7 can be executed in accordance with the thickness of the creased paper and the degree of surface roughness due to embossing or the like.

The operation screen 310 of FIG. 13 is the same screen as the operation screen 310 shown in FIG. 9, but in the state of FIG. 13, the recording paper smoothing setting indicates that recording paper smoothing printing is set as a special function. A display unit 318 is displayed. From this display, the user can confirm that the recording paper smoothing process is set. By instructing execution of copying in this state, reading and printing of the original image is executed. At this time, after the recording paper is heated and pressed by the fixing unit 7, printing of the read image data is performed. .

When canceling the recording paper smoothing printing setting on the operation screen 310 in FIG. 13, the operation screen 330 in FIG. 12 is displayed, and the setting is performed by operating the recording paper smoothing printing setting button 331 again. Can be released. Alternatively, the recording paper smoothing print setting can be canceled by operating the all cancel key 302 provided on the operation panel 300 of FIG.

DESCRIPTION OF SYMBOLS 1 ... Exposure unit, 2 ... Developing device, 3 ... Photoconductor drum, 4 ... Cleaner unit, 5 ... Charger, 6 ... Intermediate transfer belt unit, 7 ... Fixing unit, 10 ... Transfer roller, 11a, 11b ... Pickup roller, 12a, 12b, 12c, 12d ... conveying roller, 13 ... registration roller, 31, 31Y, 31M, 31C ... transfer roller arm, 31a ... lateral arm collar, 31b ... bent part, 32 ... spring, 32a, 32b ... end, 33: Transfer roller arm, 33a, 43a ... Lateral arm rod, 33b, 43b ... Bent portion, 34 ... Spring, 34a, 34b ... End portion, 35 ... Slide rod, 35a ... Right end portion, 35d ... Projection portion, 36 ... Cam shaft 37 ... Eccentric cam 38 ... Slide rod 38a ... Left side end 39 ... Eccentric cam 43 ... Backup roller arm 45 ... Tension low 45a ... lower end, 48 ... detection switch, 51 ... optical sensor, 61 ... intermediate transfer belt, 62 ... intermediate transfer belt drive roller, 63 ... intermediate transfer belt driven roller, 64 ... intermediate transfer roller, 65. Intermediate transfer belt cleaning unit, 66 ... Backup roller, 67 ... Tension roller, 71 ... Heat roller, 72 ... Pressure roller, 73 ... External heating belt, 81, 82 ... Paper feed cassette, 90 ... Image reading means, 91 DESCRIPTION OF SYMBOLS ... Paper discharge tray, 92 ... Document placing table, 93 ... Light source unit, 94 ... Mirror unit, 95 ... CCD, 100 ... Image forming apparatus, 110 ... Control unit, 130 ... Main unit, 111 ... Operation unit, 112 ... Image formation , 113 ... transfer unit, 114 ... fixing unit, 115 ... recording paper transport unit, 116 ... display unit, 117 ... image input unit, 120 Automatic manuscript processing apparatus 201 ... Print number setting unit 202 ... Double-sided printing setting unit 203 ... Setting unit 204 ... Setting unit 205 ... User setting unit 206 ... Job management unit 207 ... OK button 208 ... Recording paper Smoothing print setting unit 300 ... Operation panel 301 ... Start key 302 ... All cancel key 303 ... Clear key 304 ... Ten key 305 ... Hard key group 306 ... Operation display unit 310 ... Operation screen 311 ... Special

function setting buttons

312, 313 ... Setting buttons related to finishing, 314, 315 ... Setting buttons related to data storage, 316 ... Status display section, 317 ... Document setting button, 320 ... Setting screen, 321 ... Arrow, 331 ... Setting button, 332 ... OK button.

Claims

A recording paper transport unit that transports the recording paper; an image forming unit that forms an image on the recording paper transported by the recording paper transport unit; and a control unit that controls the recording paper transport unit and the image forming unit. An image forming apparatus,
The image forming unit is configured to transfer a toner image formed on an image carrier onto the recording paper, and heat-press the recording paper on which the toner image is transferred by the transfer unit to transfer the toner image onto the recording paper. A fixing unit for fixing,
The image forming apparatus according to claim 1, wherein the control unit performs control of heat-pressing the recording paper with the fixing unit without transferring the toner image with the transfer unit under a predetermined condition.
The image forming apparatus according to claim 1.
The recording paper transport unit has a transport path for transporting the recording paper heat-pressed by the fixing unit to the transfer unit again.
Under the predetermined conditions, the control unit transports again the recording sheet heat-pressed by the fixing unit without transferring the toner image by the transfer unit to the transfer unit, and the transfer unit transfers the recording paper to the image carrier. An image forming apparatus for transferring the formed toner image onto the recording paper.
The image forming apparatus according to claim 1, wherein
It has an operation unit that accepts user operation input,
The control unit fixes the recording paper without transferring the toner image in the transfer unit when a predetermined mode is set according to a predetermined operation input to the operation unit as the predetermined condition. An image forming apparatus characterized in that it is thermocompression-bonded at a portion.
The image forming apparatus according to claim 1, wherein
An image input unit for inputting image data to be imaged from an external device;
When the image data input from the image input unit includes instruction information for image formation in a predetermined mode as the predetermined condition, the control unit causes the transfer unit to transfer the toner image. An image forming apparatus, wherein the recording paper is heat-pressed by the fixing unit without being performed.
The image forming apparatus according to any one of claims 1 to 4,
The transfer unit transfers a plurality of image carriers, an intermediate transfer belt that transfers the toner images formed on the plurality of image carriers, and the toner images transferred to the intermediate transfer belt onto the recording paper. A transfer roller, and a drive mechanism that contacts or separates the image carrier and the intermediate transfer belt,
The image forming apparatus, wherein the drive mechanism section separates the image carrier and the intermediate transfer belt under the predetermined condition.
The image forming apparatus according to any one of claims 1 to 5,
The control unit is configured to reduce, under the predetermined condition, a conveyance speed of the recording paper that passes through the fixing unit to be lower than a conveyance speed when the transfer unit transfers the toner image onto the recording paper. Image forming apparatus.
The image forming apparatus according to any one of claims 1 to 6,
The control unit is configured to set the heating temperature of the fixing unit to be higher than the heating temperature of the fixing unit when the transfer unit transfers the toner image onto a recording sheet under the predetermined condition. Forming equipment.
Image formation performed by an image forming apparatus having a transfer unit that transfers a toner image formed on an image carrier onto the recording paper, and a fixing unit that fixes the toner image transferred by the transfer unit by thermocompression bonding A method,
Heat-pressing the recording paper at the fixing unit without transferring the toner image at the transfer unit;
A transfer step of transporting the thermocompression-bonded recording paper to the transfer unit and transferring the toner image onto the recording paper;
A fixing step of fixing the toner image transferred in the transfer step onto the recording paper by the fixing unit.