JP2008051857A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an image forming apparatus capable of yielding a smooth high-gloss image by a practical means which is not accompanied with large design change without causing trouble such as hot offset or winding and without requiring a large-scale expensive device. <P>SOLUTION: The image forming apparatus is equipped with a sheet cassette 34 in which a gloss applying sheet 33 is housed, and a second fixing device 25 which makes the gloss applying sheet extended from the sheet cassette when forming a high-gloss image pass in such a state that the gloss applying sheet is superposed on the image surface of recording material 16 on which a toner image has been fixed by a first fixing device 22 so that the toner may be melted again, and then sticks it to the recording material. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile, or a complex machine thereof. In particular, the present invention relates to an image forming apparatus using electrophotography.

  In an image forming apparatus using electrophotography, it is difficult to produce a uniform high gloss image such as a silver salt photograph. This is because the use of toner having a particle size of 5 μm or more is a major obstacle in smoothing the image surface. If the solid portion is well melted with toner, the gloss can be increased by smoothing the surface. However, in the halftone created from halftone dots and lines, the area where the toner is placed and the area where the toner is not placed are mixed on the paper. I can't.

  In view of this, a recording material such as disclosed in Patent Document 1 is used in which a thermoplastic resin coat layer is provided on the surface and toner is embedded in the coat layer to obtain a smooth surface. However, even if this recording material is used, with the fixing method using the fixing roller and fixing belt in the conventional fixing device, when the toner is sufficiently melted at a high temperature, the hot offset problem that the toner adheres to the fixing roller side, There was a problem of winding of the recording paper around the fixing roller. Furthermore, since the toner surface is peeled off from the fixing roller or the fixing belt in a state where the toner is melted at a high temperature, there is an essential problem that the surface shape is disturbed and smooth high gloss is not obtained.

  In order to solve this problem, for example, a fixing device having a heating part, a cooling part, and a peeling part provided on the circumference of a high-gloss endless belt having a smooth surface as disclosed in Patent Document 2 has been proposed. ing. In this apparatus, the toner is sufficiently melted in the heated portion so as to follow the glossy surface of the endless belt, the toner is solidified in the cooling unit, and the glossy surface of the endless belt is copied, and the endless belt and the toner surface are separated in the peeling unit. To peel off. As a result, a smooth toner surface was obtained, and as a result, a smooth high gloss image was obtained.

  Actually, this fixing device has been successfully commercialized, and is installed as a digital camera print in a convenience store. However, this method requires a large-scale device, and issues remain in terms of cost and size.

  In addition to the above, many electrophotographic image forming apparatuses having a laminating function have been proposed as disclosed in Patent Document 3 and Patent Document 4, for example. However, these have been hardly used because they require a large-scale device and are not practical, and some users do not like laminated images.

JP 63-92965 A JP 2002-91048 A JP-A-9-150456 Japanese Patent No. 3213969

  To solve the problem that if the toner surface is peeled off from the fixing roller or the fixing belt in a state where the toner is melted at a high temperature, the surface shape is disturbed and the high gloss is not obtained, Patent Document 2 discloses. As described above, after the toner is melted so as to follow a smooth high gloss surface, the toner must be cooled and solidified and then peeled off.

  Accordingly, an object of the present invention is to make a large design change in an image forming apparatus without requiring a large and expensive apparatus as described in Patent Document 2 and without causing problems such as hot offset and winding. The object is to make it possible to obtain a smooth high-gloss image by a practical means that is not accompanied.

In order to achieve this object, the present invention provides a recording material such as paper having a toner image on the image surface through a fixing device to melt the toner and fix the toner image on the recording material. In an image forming apparatus that discharges to a post-processing apparatus or the like,
The sheet cassette for storing the gloss imparting sheet and the gloss imparted sheet fed from the sheet cassette are overlapped on the image surface of the recording material after being fixed by the fixing device as the first fixing device, and the toner is melted again. And a second fixing device that bonds the gloss-imparting sheet to the recording material.

  Then, the recording material having the toner image on the image surface is passed through the first fixing device, the toner is once melted, the toner image is fixed on the recording material, and then the recording material image fixed by the first fixing device. The glossy sheet fed from the sheet cassette is superposed on the surface and passed through the second fixing device, and the toner is melted again and the glossy sheet is bonded to the recording material. The application sheet is peeled off and then discharged.

  As the gloss imparting sheet, it is preferable to use a sheet obtained by applying a release agent on the surface of the recording material that is to be superimposed on the image surface. The image forming apparatus includes, for example, a first image forming mode for discharging only through the first fixing device, and a second image forming mode for discharging through both the first fixing device and the second fixing device. The image forming mode can be selected and used.

  Further, the first fixing device and the second fixing device are operated by a common one fixing device, and the recording material after passing through the fixing device for the first time passes through the conveyance path for double-sided image formation and is given gloss. The sheets can be overlapped and passed through the fixing device again for the second time and discharged. Here, the double-sided image forming conveyance path may be provided with a switching member for switching the conveyance path of the recording material according to the double-sided image forming mode and the high gloss image forming mode.

  It should be noted that the gloss-imparting sheet that is superimposed on the recording material and passed through the second fixing device may be stored in the sheet cassette again after being peeled from the recording material.

  According to the first aspect of the present invention, the toner is once melted and the toner image is fixed on the recording material, and then the toner is melted again and the glossy sheet is bonded to the recording material. The toner can be sufficiently dissolved at a high temperature without worrying about such problems. Since the surface of the melted toner is hardened following the smooth sheet surface of the gloss-imparting sheet, a uniform and smooth high-gloss image can be obtained. Further, since the configuration of a conventional general fixing device can be used, a practical device that does not require a large and expensive device and does not require a large design change can be provided. For example, there is an advantage that if the gloss-imparting sheet is attached to the recording material and discharged, the toner can be output at high speed without providing a cooling time for the toner to harden.

  According to the second aspect of the present invention, since the gloss-imparting sheet formed by applying the release agent to the surface of the recording material that is to be superimposed on the image surface is used, the release agent can increase the adhesion of the toner to the gloss-giving sheet. When the gloss-imparting sheet is peeled off from the recording material by weakening, the toner does not adhere to the gloss-imparting sheet side, and the deterioration of the image quality can be prevented.

  According to the third aspect of the present invention, the first image forming mode for discharging only through the first fixing device to the image forming apparatus, and the second image forming mode for discharging through both the first fixing device and the second fixing device. Thus, a single image forming apparatus can selectively output recording materials for both low-gloss images and high-gloss images, and the application of the image forming apparatus can be expanded.

  According to the fourth aspect of the invention, since the function of the first fixing device and the second fixing device is performed by one common fixing device, the size of the fixing device can be reduced and the cost can be reduced. . In addition, since the recording material after passing through the fixing device for the first time is passed through the double-sided image forming conveyance path, the glossy sheet is overlapped, and then passed again through the fixing device for the second time. By using the forming apparatus, a uniform and smooth high-gloss image can be obtained without significant design change.

  According to the fifth aspect of the present invention, for example, the double-sided image forming transport path of the double-sided unit includes the switching member for switching the recording material transport path according to the double-sided image forming mode and the high-gloss image forming mode. In the image forming mode, the sheet cassette after passing through the fixing device for the first time can be fed again without reversing, so that the feeding direction of the glossy sheet is the same as the feeding direction of the recording material. The image forming apparatus can be installed so as to be overlapped with the recording material accommodation cassette, and the image forming apparatus can be downsized by enabling high-density component arrangement.

  According to the sixth aspect of the present invention, since the gloss-imparting sheet can be accommodated again in the sheet cassette after use, it is possible to reduce the cost without making it disposable and to meet the recent social demand for resource protection. it can.

The best mode for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 shows an overall schematic configuration of an electrophotographic image forming apparatus according to the present invention.

  An image forming apparatus main body 10 denoted by reference numeral 10 in the drawing is provided with a process unit 12 in a detachable manner in the middle stage. The process unit 12 is provided with a drum-shaped photoconductor 13 so as to be rotatable. Although not shown, the process unit 12 includes a charging device, a developing device, and the like. Although not shown, a writing device is installed near the process unit 12. Then, a roller-shaped transfer device 14 disposed across the recording material conveyance path P is pressed against the photoreceptor 13 of the process unit 12 to form a transfer nip.

  Further, in the image forming apparatus main body 10, recording material accommodation cassettes 15 are stacked in three stages below the process unit 12 and are detachably provided. Each recording material accommodation cassette 15 is loaded with, for example, recording materials 16 of different sizes. Generally, paper is used as the recording material 16. Each of the recording material accommodation cassettes 15 individually corresponds to a paper feed roller 17 for feeding out the recording material 16 to be accommodated, and a pair of conveyance rollers for feeding the fed recording material 16 into the recording material conveyance path P and conveying it upward. 18

  A registration roller pair 20 is provided in front of the transfer nip and a first fixing device 22 is provided after passing through the transfer nip in the recording material conveyance path P that extends from the lower side to the upper side in the right side in the image forming apparatus main body 10. The first fixing device 22 is configured by forming a first fixing nip by urging a first heating roller 23 containing a heater with an urging member (not shown) and pressing the first pressure roller 24. It becomes.

  A second fixing device 25 is provided downstream of the first fixing device 22 along the recording material conveyance path P. Similarly, in the second fixing device 25, a second fixing nip is formed by urging the second heating roller 26 incorporating a heater with a urging member (not shown) and pressing the second pressure roller 27. Consists of. Further, a paper discharge roller pair 28 is provided downstream of the second fixing device 25, and a paper discharge port 31 is subsequently provided toward the paper discharge stack portion 30 on the image forming apparatus main body 10.

  By the way, the gloss imparting sheet 33 can be joined to the recording material conveyance path P between the first fixing device 22 and the second fixing device 25 so as to overlap the image surface of the recording material 16. The gloss imparting sheet 33 is a sheet having a smooth surface, and is stacked and accommodated in a sheet cassette 34 that is detachably provided above the process unit 12, and is synchronized with the recording material 16 that is conveyed on the recording material conveyance path P. Then, the paper is fed by the feed roller 35 and is transported by the transport roller pair 36 so that it can enter the recording material transport path P.

  When a low gloss image is formed on the recording material 16 by the illustrated image forming apparatus, the first image forming mode in which the sheet is discharged only through the first fixing device 22 by a signal from the host or an operation display panel (not illustrated) is set. . Then, the process unit 12 is driven to rotate the photoconductor 13 counterclockwise, and charging, writing, and development are performed by a process device such as a charging device, a writing device, and a developing device to form a toner image on the photoconductor 13. To do. On the other hand, one of the paper feed rollers 17 is selectively driven to feed the recording material 16 from the corresponding recording material storage cassette 15 into the recording material conveyance path P, and conveyed by the conveyance roller pair 18 to register the leading end. It strikes against the roller pair 20.

  After that, the registration roller pair 20 is rotated so as to match the timing of the toner image formed on the rotating photoconductor 13 as described above, and the recording material 16 is fed into the transfer nip to transfer the toner image on the photoconductor 13. The image is transferred to the recording material 16 by the apparatus 14. The recording material having a toner image on its image surface is transferred to the first fixing device 22 through the recording material conveyance path P, and heat and pressure are applied by the first heating roller 23 and the first pressure roller 24. In addition, the toner is melted to fix the toner image on the recording material 16.

  After the toner image is fixed, the recording material 16 is conveyed through the recording material conveyance path P as it is, and is discharged from the paper discharge port 31 by the paper discharge roller pair 28 through the second fixing device 25 that is not operating, that is, not generating heat. Are stacked on the paper discharge stack unit 30.

  On the other hand, when a high gloss image is formed on the recording material 16 by the illustrated image forming apparatus, the image is discharged through both the first fixing device 22 and the second fixing device 25 by a signal from the host or an operation of an operation display panel (not illustrated). The second image forming mode is set. Similarly, the toner image formed on the photosensitive member 13 is transferred to the recording material 16 fed out from one of the recording material accommodation cassettes 15, and once the toner is melted and fixed by the first fixing device 22, the fixing is performed. The gloss imparted sheet 33 fed from the sheet cassette 34 is superimposed on the image surface of the subsequent recording material 16 and placed in the second fixing device 25, and heat and pressure are applied by the second heating roller 26 and the second pressure roller 27. Then, the toner is sufficiently melted again at a high temperature and the gloss imparting sheet 33 is bonded to the recording material 16. Similarly, the paper is discharged from the paper discharge port 31 by the paper discharge roller pair 28 and stacked on the paper discharge stack unit 30.

  Thereafter, the temperature of the recording material 16 to which the gloss imparting sheet 33 is bonded is lowered to such an extent that the toner hardens, and then the gloss imparting sheet 33 is peeled off. It is also possible to provide a process for automatically removing the gloss-imparting sheet 33 from the recording material 16 before discharging from the discharge port 31 by the discharge roller pair 28. By doing so, it is possible to save the user from having to peel off the gloss imparting sheet 33 from the recording material 16. However, in this case, it is necessary to wait for the temperature to drop before the gloss-imparting sheet 33 is peeled off.

  As described above, according to the illustrated image forming apparatus, the toner is once melted and the toner image is fixed on the recording material 16, and then the toner is melted again and the gloss imparting sheet 33 is bonded to the recording material 16. The toner can be sufficiently dissolved at a high temperature without worrying about problems such as hot offset and winding. Since the surface of the melted toner is copied and smoothed by copying the smooth surface of the gloss imparting sheet 33, a uniform and smooth high gloss image can be obtained in the solid portion, halftone portion, and non-image portion. it can. In particular, as described in Patent Document 1, it is more effective when a recording material that provides a smooth image surface by providing a thermoplastic resin coating layer on the surface and embedding toner in the coating layer is more effective. .

  In addition, since the configuration of a conventional general fixing device can be used, a large-scale and expensive device is not required, and a practical device without a large design change can be obtained. For example, if the gloss imparting sheet 33 is attached to the recording material 16 and discharged, there is an advantage that the toner can be output at high speed without providing a cooling time for the toner to harden.

  Here, when the gloss-imparting sheet 33 formed by applying a release agent to the surface of the recording material 16 to be superimposed on the image surface is used, the adhesive force of the toner to the gloss-imparting sheet 33 is weakened by the release agent, and the recording material 16 When the gloss-imparting sheet 33 is peeled off from the toner, the toner does not adhere to the gloss-imparting sheet 33 side, and deterioration of image quality can be prevented.

  If the gloss-imparting sheet 33 that has been peeled off from the recording material 16 can be accommodated again in the sheet cassette 34 that has been removed from the image forming apparatus main body 10 after use, it is possible to reduce costs and reduce resource consumption. It can meet recent social demands for effective use.

FIG. 2 shows an overall schematic configuration of another example of the electrophotographic image forming apparatus according to the present invention.
In the image forming apparatus shown in FIG. 2, the functions of the first fixing device 22 and the second fixing device 25 shown in FIG. 1 are performed by a single fixing device 40, and a heating roller 41 containing a heater is not shown. The second fixing nip is formed by pressing the pressing roller 42 with the biasing member.

  Further, the sheet cassette 34 for storing the gloss imparting sheet 33 is disposed on the side opposite to the process unit 12 side with respect to the recording material transport path P, and the gloss imparting sheet 33 fed by the feed roller 35 is disposed on the pair of transport rollers. The sheet is conveyed at 36 and is placed in the recording material conveyance path P before the registration roller pair 20.

  Further, a duplex unit 50 is attached to the right side surface of the image forming apparatus main body 10. The double-sided unit 50 is provided with a double-sided image forming conveyance path P1, and the double-sided image forming conveyance path P1 includes a unit switching claw 51, a reverse roller pair 52, a switchback path 53, and a refeeding path 54. And a plurality of pairs of refeed rollers 55. A main body switching claw 43 is provided in the image forming apparatus main body 10 downstream of the fixing device 40, and the recording material 16 after fixing is discharged toward the paper discharge stack unit 30 by switching the main body switching claw 43. Or can be fed into the duplex unit 50.

  When a low gloss image is formed on one side of the recording material 16 by the illustrated image forming apparatus, the first image forming mode is set by a signal from the host, an operation of an operation display panel (not shown), or the like. Then, the process unit 12 is driven to rotate the photoconductor 13 counterclockwise, and charging, writing, and development are performed by a process device such as a charging device, a writing device, and a developing device to form a toner image on the photoconductor 13. To do. On the other hand, one of the paper feed rollers 17 is selectively driven to feed the recording material 16 from the corresponding recording material storage cassette 15 into the recording material conveyance path P, and conveyed by the conveyance roller pair 18 to register the leading end. It strikes against the roller pair 20.

  After that, the registration roller pair 20 is rotated so as to match the timing of the toner image formed on the rotating photoconductor 13 as described above, and the recording material 16 is fed into the transfer nip to transfer the toner image on the photoconductor 13. The image is transferred to the recording material 16 by the apparatus 14. The recording material having the toner image on its image surface is transferred to the fixing device 40 through the recording material conveyance path P, and heat and pressure are applied between the heating roller 41 and the first pressure roller 42 to remove the toner. The toner image is fixed on the recording material 16 by melting.

  After the toner image is fixed, the recording material 16 is directly conveyed on the recording material conveyance path P, switched by the main body switching claw 43 and directed to the paper ejection port 31, and ejected through the paper ejection port 31 by the paper ejection roller pair 28. Stack on the stack unit 30.

  When low gloss images are formed on both sides of the recording material 16, the third image forming mode is set by a signal from the host or an operation display panel (not shown). Then, the recording material 16 after the one-side toner image is formed is switched by the main body switching claw 43 and conveyed toward the duplex unit 50.

  Then, the recording material 16 sent to the duplex image forming conveyance path P1 of the duplex unit 50 is once sent to the switchback path 53 by the reverse roller pair 52, and then the reverse roller pair 52 is reversed to switch the unit switching claw 51. Then, the recording material 16 that has been switched back is put into the refeed path 54 and conveyed by the refeed roller pair 55, reversed, and returned to the image forming apparatus main body 10.

  The recording material 16 returned to the image forming apparatus main body 10 is sent out toward the transfer nip with timing by the registration roller pair 20, and a toner image separately formed on the photosensitive member 13 is transferred to the back surface of the recording material 16 by the transfer device 14. Is also transferred to the fixing device 40 through the recording material conveyance path P, and heat and pressure are applied by the heating roller 41 and the first pressure roller 42 to melt the toner again to fix the toner image on the recording material 16. Thereafter, the main body switching claw 43 is switched, and the paper discharge roller pair 28 discharges the paper through the paper discharge port 31 to be stacked on the paper discharge stack unit 30.

  On the other hand, when a high gloss image is formed on the recording material 16 by the illustrated image forming apparatus, the second image forming mode is set by a signal from the host or an operation on an operation display panel (not shown). Similarly, the toner image formed on the photosensitive member 13 is transferred to the recording material 16 fed out from one of the recording material accommodation cassettes 15, the toner is once melted and fixed by the fixing device 40, and then the main body switching claw 43. To switch to the duplex unit 50.

  Then, the recording material 16 fed to the duplex unit 50 is similarly reversed by the duplex unit 50 and returned to the image forming apparatus main body 10. Then, the gloss imparting sheet 33 fed from the sheet cassette 34 is placed on the recording material conveyance path P and superimposed on the image surface of the recording material 16 returned to the image forming apparatus main body 10, and the registration roller pair 20 is operated. After passing through the transfer nip between the unprocessed process unit 12 and the transfer device 14, it is inserted again into the fixing device 40, and heat and pressure are applied by the heating roller 41 and the pressure roller 42 to sufficiently melt the toner again at a high temperature. Then, the gloss imparting sheet 33 is bonded to the recording material 16. Thereafter, similarly, switching is performed by the main body switching claw 43, and the paper is discharged through the paper discharge port 31 by the paper discharge roller pair 28 and stacked on the paper discharge stack unit 30.

  The recording material 16 to which the gloss imparting sheet 33 is bonded is peeled off after the temperature is lowered to such an extent that the toner hardens. As in the previous example, a process for automatically peeling the gloss-imparting sheet 33 from the recording material 16 before discharging from the paper discharge port 31 by the paper discharge roller pair 28 may be provided. Similarly, in this case, it is necessary to wait for the temperature to drop before the gloss imparting sheet 33 is peeled off.

  By the way, in this example, when the recording material 16 passes the fixing device 40 for the first time, the image surface of the recording material 16 is on the heating roller 41 side, but when the recording material 16 passes the second time, it is reversed. Thus, the pressure roller can be used as a heat generating roller so that the back surface of the recording material 16 can be directly heated when passing through the fixing device for the second time. There is a need.

  Even in this example, the toner can be sufficiently dissolved at a high temperature without worrying about problems such as hot offset and winding, and a uniform and smooth high-gloss image can be obtained in the solid portion, halftone portion, and non-image portion. Can do. In particular, as described in Patent Document 1, the effect is great when a recording material is used in which a thermoplastic resin coating layer is provided on the surface and toner is embedded in the coating layer to obtain a smooth image surface.

  FIG. 3 shows an overall schematic configuration of still another example of the electrophotographic image forming apparatus according to the present invention. This example has basically the same configuration as the example shown in FIG. 2, and the reference numerals used for the corresponding parts in FIG. 2 are used as they are.

  In this example, the uppermost recording material storage cassette 15 is used as a sheet cassette 34 for storing the gloss imparting sheet 33, and in the example shown in FIG. 2, on the side opposite to the process unit 12 with respect to the recording material conveyance path P. The arranged sheet cassette 34 is arranged on the same side as the process unit 12. Similarly, the gloss imparting sheet 33 fed by the feeding roller 35 is placed in the recording material conveyance path P before the registration roller pair 20.

  In the example shown in FIG. 2, the first posture for guiding the recording material 16 fed into the duplex unit 50 to the switchback path 53 and the recording material 16 switched back from the switchback path 53 are guided to the refeed path 54. Although the unit switching claw 51 for switching to the second posture is provided, another unit switching claw 56 is provided in place of the unit switching claw 51.

  Similar to the unit switching claw 51 shown in FIG. 2, the unit switching claw 56 is fed into the duplex image forming conveyance path P1 of the duplex unit 50 as shown in FIG. 4A in the third image forming mode. A first posture for guiding the recording material 16 to the switchback path 53 and a second posture for guiding the recording material 16 switched back from the switchback path 53 to the refeed path 54 as shown in FIG. As shown in FIG. 6, the recording material 16 fed into the duplex unit 50 can be switched to the third posture that directly leads to the refeed path 54.

  When a low gloss image is formed on one side and both sides of the recording material 16 by the illustrated image forming apparatus, the first image forming mode or the third image forming mode is performed in the same manner as in the example shown in FIG. However, when a high-gloss image is formed, the unit switching claw 56 is set to the third posture shown in FIG. 5 as the second image forming mode by a signal from the host or an operation display panel (not shown).

  Then, the toner image formed on the photosensitive member 13 is transferred to the recording material 16 fed out from one of the recording material storage cassettes 15, the toner is once melted and fixed by the fixing device 40, and then switched by the main body switching claw 43. However, the recording material 16 fed to the duplex unit 50 is directly guided to the refeed path 54 without being switched back, and is conveyed by the conveyance roller pair 55 and reversed. Return to the image forming apparatus main body 10 without doing so.

  Then, the gloss imparting sheet 33 fed from the sheet cassette 34 is placed on the recording material conveyance path P and superimposed on the image surface of the recording material 16 returned to the image forming apparatus main body 10, and the registration roller pair 20 is operated. After passing through the transfer nip between the unprocessed process unit 12 and the transfer device 14, it is inserted again into the fixing device 40, and heat and pressure are applied by the heating roller 41 and the pressure roller 42 to sufficiently melt the toner again at a high temperature. Then, the gloss imparting sheet 33 is bonded to the recording material 16. Thereafter, similarly, switching is performed by the main body switching claw 43, and the paper is discharged through the paper discharge port 31 by the paper discharge roller pair 28 and stacked on the paper discharge stack unit 30.

  The recording material 16 to which the gloss imparting sheet 33 is bonded is peeled off after the temperature is lowered to such an extent that the toner hardens. Also in this case, as in the previous example shown in FIGS. 1 and 2, a process for automatically peeling the glossy sheet 33 from the recording material 16 is provided before the paper discharge roller pair 28 discharges from the paper discharge port 31. Similarly, it is necessary to wait for the temperature to drop before the gloss imparting sheet 33 is peeled off.

  Even in this example, the toner can be sufficiently dissolved at a high temperature without worrying about problems such as hot offset and winding, and a uniform and smooth high-gloss image can be obtained in the solid portion, halftone portion, and non-image portion. Can do. In particular, as described in Patent Document 1, the effect is great when a recording material is used in which a thermoplastic resin coating layer is provided on the surface and toner is embedded in the coating layer to obtain a smooth image surface.

  In addition, according to this example, the double-sided image forming transport path P1 provided in the double-sided unit 50 is provided with the unit switching claw 56 for switching the transport path of the recording material 16 according to the double-sided image forming mode and the high gloss image forming mode. The high-gloss image forming mode allows the recording material 16 that has been fixed to pass through the fixing device 40 for the first time to be fed again without being reversed. The sheet cassette 34 can be placed on the recording material storage cassette 15 in the same manner as described above, and the image forming apparatus can be miniaturized by enabling high-density component placement without complicating the configuration.

  In the example shown in FIG. 2, the image surface is turned over when the recording material 16 passes through the fixing device 40 for the first time and when the recording material 16 passes for the second time. For example, the pressure roller needs to be a heating roller. However, according to this example, since the image surface is the same side when passing the first time and when passing the second time, only the heating roller 41 needs to be a heat generating roller. Can be simple.

1 is an overall schematic configuration diagram of an electrophotographic image forming apparatus according to the present invention. It is a whole schematic block diagram of the other example of the electrophotographic image forming apparatus which concerns on this invention. FIG. 7 is an overall schematic configuration diagram of still another example of the electrophotographic image forming apparatus according to the present invention. (A) is explanatory drawing when a unit switching claw is made into the 1st posture in the double-sided image formation mode, and (B) is a case where it makes the 2nd posture. It is explanatory drawing when a unit switching nail | claw is made into the 3rd attitude | position in the high gloss image formation mode.

Explanation of symbols

16 recording material 22 first fixing device 25 second fixing device 33 gloss imparting sheet 34 sheet cassette 40 fixing device 50 duplex unit 56 unit switching claw (switching member)
P1 Double-sided image forming transport path

Claims (6)

In an image forming apparatus that melts toner by passing a recording material having a toner image on an image surface through a fixing device, and fixes and discharges the toner image on the recording material.
The sheet cassette for storing the gloss-imparting sheet and the gloss-giving sheet fed out from the sheet cassette are overlapped on the image surface of the recording material after being fixed by the fixing device as the first fixing device, and the toner is again supplied. An image forming apparatus comprising: a second fixing device that melts and attaches the gloss imparting sheet to a recording material.   2. The image forming apparatus according to claim 1, wherein the gloss imparting sheet is a sheet formed by applying a release agent on a surface to be superimposed on an image surface of a recording material.   The first image forming mode for discharging only through the first fixing device and the second image forming mode for discharging through both the first fixing device and the second fixing device are provided. The image forming apparatus according to 2.   The first fixing device and the second fixing device are operated by one common fixing device, and the recording material after passing through the fixing device for the first time passes through the conveyance path for double-sided image formation and then the gloss. The image forming apparatus according to claim 1, wherein the application sheets are superposed and discharged through the fixing device a second time.   5. The image forming apparatus according to claim 4, wherein the double-sided image forming conveyance path includes a switching member that switches a recording material conveyance path according to a double-sided image forming mode and a high-gloss image forming mode.   The image forming apparatus according to claim 1, wherein the gloss imparting sheet can be accommodated in the sheet cassette again after use.

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