JPH06324600A - Image forming device - Google Patents

Abstract

PURPOSE:To provide an image forming device, having two or more built-in developing devices that use a color-extinguishing toner and a normal toner and capable of forming images by selecting either the color--extinguishing or normal toner without varying fixing conditions. CONSTITUTION:In an image forming device having two or more built-in developing devices 1, 2 that use a color-extinguishing toner and a normal toner, and having a heat roller fixing device 11, the softening temperature of the color- extinguishing toner is almost the same as that of the normal toner. Since the color-extinguishing toner and the normal toner have almost the same softening temperature, the necessity of varying fixing conditions from the color- extinguishing toner to the normal toner is eliminated, no waiting time for varying fixing conditions is needed, and the necessity of complex mechanisms and control means for varying fixing conditions is eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus capable of forming an image by arbitrarily selecting an erasable toner and a non-erasable toner (normal toner).

[0002]

2. Description of the Related Art In recent years, paper wastes discharged from offices have been attracting attention from the viewpoint of resource conservation in the problem of wastes becoming serious. The recycling of paper, so-called OA paper, is being called for. Therefore, in the office, an OA paper is printed by using a toner using a decolorizable colorant, that is, a so-called decoloring toner, and erasing and printing again when no longer needed.
Paper recycling is proposed. An outline of this decolorizable toner is one in which a colorant composed of a cyanine dye and an ammonium salt of organic boron is dispersed in a transparent resin, and in an electrophotographic image forming apparatus, a colorant of carbon black When a toner containing the above colorant is used instead, blue printing is possible under general illumination, and the same visibility as in normal recording is obtained. In this print recording method, the colorant can be made colorless by irradiating light near 820 nm, so that the recording can be erased. Therefore, by using such a recording material of a color erasable colorant, it is possible to reuse recycled paper relatively easily,
It is said to be effective in resource conservation, environmental conservation, and reduction of municipal solid waste.

Since the color-erased toner image is made transparent by the action of light irradiation or heat, if the recording paper having the color-erasable toner image having a light-color erasability is left in a bright place, the toner image will gradually fade, It becomes transparent at the end. Further, the heat-decolorable toner image becomes transparent when it is stored in a place of high temperature for a long time. Therefore, decolorizable toners are essentially unsuitable for forming images with important content that needs to be preserved. In this case, if the toner that can be used in the image forming apparatus is only the decoloring toner, the image formation of the image information for storage must be performed by another dedicated image forming apparatus. Therefore, in order to solve such a problem, the applicant first
Two or more developing devices using decoloring toner and non-decoloring toner (normal toner) are built in, and an image can be formed by arbitrarily selecting decoloring toner and non-decoloring toner (normal toner). An image forming apparatus was proposed (Japanese Patent Application No. 4-2986).
No. 13, etc.).

[0004]

By the way, in an image forming apparatus having two or more developing devices using a decolorizable toner and a non-decolorable toner (normal toner), a developing device using the decolorizable toner is used. When A is used and B is a general developing device that normally uses toner, both A and B are set in the image forming apparatus, and A and B are selected by the operation unit. At this time, if the temperature characteristics of the toners contained in A and B are different,
It is necessary to change the fixing conditions depending on the toner used.
For example, when the selection of A and B is frequently changed, the fixing condition is frequently changed, and when the fixing temperature is raised or lowered as a fixing condition, a waiting time occurs, and the fixing linear velocity is changed. In this case, since the distance between the transfer portion and the fixing portion is sufficiently large, the device becomes large. Further, in the case of the two developing devices A and B, if the toners of the same color are used, it cannot be distinguished which image is formed by the decoloring toner, and reuse becomes difficult, and the original purpose is lost. There is a problem. Further, as another problem, there is a problem that offset and odor of the decolorizable toner are likely to occur during fixing.

The present invention has been made in view of the above circumstances, and it incorporates two or more developing devices using a decoloring toner and a normal toner, and the decoloring toner and the normal toner can be arbitrarily changed without changing the fixing conditions. And an image forming apparatus capable of forming an image with a decoloring toner, and easily distinguishing a recorded matter by forming an image with a decoloring toner, and capable of solving a problem when the decoloring toner is used. The purpose is to provide.

[0006]

In order to achieve the above object, in the present invention, two or more developing devices using decolorizing toner and non-decoloring toner (normal toner) are built in, and a heat roller fixing device is provided. In the image forming apparatus having the same, the decolorizing toner and the normal toner have substantially the same softening temperature (Claim 1). Further, in the image forming apparatus, the color of the decoloring toner and the color of the normal toner are changed (claim 2). In the image forming apparatus, when the decoloring toner and the normal toner have the same color, the recording material on which the image is formed by the decoloring toner is marked so as to be distinguishable from the image by the normal toner. . Also, as the marking method,
In the case of a digital machine, image information is output from built-in software to form an image (claim 4).

Further, in the image forming apparatus, the cleaning roller, the oil applying roller, or the oil applying / cleaning roller is brought into contact with the fixing roller of the fixing device only when the decoloring toner is used (claim 5). In the image forming apparatus, a deodorizing member is provided near the fixing device (claim 6). Further, the deodorizing member and the exhaust fan are used together (claim 7).

[0008]

In the image forming apparatus of the present invention, since the softening temperatures of the decoloring toner and the normal toner are substantially the same, it is not necessary to change the fixing conditions for the decoloring toner and the normal toner. Also, by changing the color of decolorizing toner and normal toner,
It is easy to distinguish the image with the decoloring toner and the image with the normal toner. Further, when the decoloring toner and the normal toner have the same color, the marking can be put on the recording material on which the image is formed by the decoloring toner to facilitate the discrimination. As a marking method, an analog type image forming apparatus can use an eraser for marking, and a digital type image forming apparatus can easily perform marking by outputting image information from built-in software to form an image. You can

Further, since the decoloring toner has a poor releasability,
Although it is necessary to apply oil to the fixing roller, the toner usually has good releasability and does not require oil application.Therefore, the cleaning roller or oil application roller or oil application / cleaning is only applied to the fixing roller of the fixing device when decolorizing toner is used. Contact the rollers. As a result, wasteful consumption of the cleaning roller, the oil application roller, or the oil application / cleaning roller can be prevented, and the service life can be extended. Further, although the decoloring toner has a problem of odor, in the present invention, this problem can be solved by providing a deodorizing member in the vicinity of the fixing device and further using a deodorizing member and an exhaust fan together.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on the illustrated embodiments. FIG. 1 is a diagram showing an embodiment of the present invention, (a) is a schematic configuration diagram showing an example of an electrophotographic image forming apparatus such as a copying machine, and (b) is a schematic diagram showing an example of a developing device. It is a block diagram. In FIG. 1, reference numeral 1 is a developing device for normal toner that develops with normal toner, 2 is a developing device for decoloring toner that develops with decoloring toner, 3 is a photosensitive drum that is an electrostatic latent image carrier, and 4 Is the photoconductor drum 3
For uniformly charging the sheet, 5 is a sheet feeding cassette containing recording sheets, 6 is a sheet feeding roller, 7 is a registration roller, 8 is a sheet for transferring the toner image on the photoconductor onto the recording sheet. A transfer charger, 9 is a separation charger for separating the recording paper after transfer from the photoconductor, 10 is a transport unit, 11 is a fixing device for fixing an unfixed toner image on the recording paper, and 12 is a residue on the photoconductor. A cleaning device for removing toner, 13 is a charge eliminating device for eliminating residual charges on the photoconductor, 15 is an eraser for erasing the non-image area on the photoconductor, and 16 is an exhaust fan. Further, a portion indicated by reference numeral 14 is an exposure optical system for an original image when the image forming apparatus is an analog type, and when the image forming apparatus is a digital type, optical writing is performed by deflecting and scanning a laser beam or the like modulated according to image information. And an optical scanning optical system for performing.

The normal toner developing device 1 is composed of a developing sleeve 1a, a paddle 1b, a mixing roller 1c, a toner replenishing roller 1d, a toner tank 1e, etc. in the illustrated example, and the toner replenishing roller 1d from the toner tank 1e. The replenished normal toner is stirred and mixed by the mixing roller 1c,
The electrostatic latent image on the photoconductor is developed by the normal toner carried by the developing sleeve 1a and drawn up by the paddle 1b and supplied to the developing sleeve 1a. Similarly, the developing device 2 for decolorizing toner also has a developing sleeve 2a and a paddle 2
b, a mixing roller 2c, a toner replenishing roller 2d, a toner tank 2e, and the like.
The decoloring toner replenished from the toner tank 2e is stirred and mixed by the mixing roller 2c, pumped up by the paddle 2b and supplied to the developing sleeve 2a, and carried by the developing sleeve 2a.
The electrostatic latent image on the photoconductor is developed by the conveyed decoloring toner. Further, as shown in FIG. 2, for example, the fixing device 11 has a configuration including a heat fixing roller 17 having a heater 21 built therein, a pressure roller 18, and an oil applying roller (or an oil applying / cleaning roller) 19. There is. The configuration of the image forming apparatus and the configurations of the developing device and the fixing device are not limited to those shown in the drawings, and various configurations can be implemented as long as they include a developing device for normal toner and a developing device for decolorizing toner. .

The image forming apparatus shown in FIG. 1 includes a developing device 1 for a normal toner and a developing device 2 for a decoloring toner, and the decoloring toner and the normal toner are arbitrarily selected by an operation unit (not shown). The image is formed by an electrophotographic method. That is, when either the decoloring toner or the normal toner is selected by the operation unit and then the image forming process is executed, first, the photoconductor drum 3 is uniformly charged by the charging charger 4, and the exposure of the original image or the image information is performed. Is written to form an electrostatic latent image. And
After the non-image area is erased by the eraser 15,
The electrostatic latent image on the photoconductor is developed by the developing device 1 or 2 selected by the operation unit to form a toner image. And
The toner image on the photoconductor is transferred to the recording paper fed from the paper feeding cassette 5 by the transfer charger 8. After transfer,
The recording paper is separated from the photosensitive drum 3 by the separation charger 9 and the separation claw, and is conveyed to the fixing device 11 via the conveyance unit 10, and the heat fixing roller 17 and the pressure roller 18 heat and press the unfixed toner image. Then, it is fixed on the recording paper. Further, the photoconductor drum 3 after the transfer is cleaned by the cleaning device 12, and then the charge is removed by the charge removing device 13 to be in a standby state for the next image forming process.

As described above, in the image forming apparatus of the present invention, an image can be formed by arbitrarily selecting either decolorizing toner or normal toner. However, if there is a difference in the softening temperature between the decoloring toner and the normal toner, the above-mentioned problems occur. Therefore, in order to solve this problem in the present invention,
The softening temperatures of the decoloring toner and the normal toner are made substantially the same so that the fixing can be performed without changing the fixing conditions such as the fixing linear velocity, the nip width and the fixing temperature. Here, as a method of making the softening temperatures of the decoloring toner and the normal toner substantially the same, the softening points of the resins constituting the toner may be set to the same temperature, and such a resin material may be selected.

When the two developing devices are built in the image forming apparatus, it may not be possible to distinguish which one is the decoloring toner. Therefore, this problem can be solved by changing the colors of the normal toner and the decoloring toner. Specifically, the decoloring toner may be blue and the normal toner may be black. However, there are cases where it is desired to use the normal toner and the decoloring toner in the same color. Therefore, in this case, as a way of distinguishing which is the image with the decoloring toner, a marking is made on a part of the recording paper so that the use of the decoloring toner can be recognized. As a specific method, as shown in FIG. 3A, in the case of an image with a decoloring toner, printing is performed on the edge of the recording paper. For this printing, when the image forming apparatus is a digital machine, the printing pattern may be stored in advance in the built-in software, and when the decoloring toner is selected, the printing pattern may be ejected to form an image. Also, in the case of an analog machine, when erasing the non-image area of the photoconductor drum 3 when the decoloring toner is selected, the eraser 15 is controlled to provide a part of the leading end erase part that does not erase.
As shown in (b), a solid image may be printed on a part of the leading edge of the recording paper to mark it.

Next, since the decoloring toner has a poor releasability, there is a problem of offset at the time of fixing. Therefore, as in the fixing device shown in FIG. 2, it is necessary to bring the oil applying roller (or the oil applying / cleaning roller) 19 into contact with the fixing roller 17 to apply the silicone oil or the like, but normally toner is releasable. Is good and does not require oil application,
The oil applying roller 19 is brought into contact with the fixing roller 17 of the fixing device only when the decoloring toner is used, and the contact of the oil applying roller 19 is released when the normal toner is used. As described above, when the toner is normally of the separable type and the release agent is not required, it is useless to always supply the oil by the oil application roller 19, and the waste of the oil can be avoided by properly using the type of toner. Prevents wear of the coating roller. The oil application roller 19 may be brought into contact with or not in contact with the fixing roller 17 by a solenoid (not shown) or the like.

Next, as a problem in using the color erasing toner, there is a problem that the color erasing toner generates a slight odor during fixing. This seems to be the odor of the monomer of the resin component that constitutes the decolorizable toner.
As shown in FIG. 5, the problem can be solved by mounting the deodorizing member 20 in which paper is impregnated with activated carbon inside the fixing device 11. As another embodiment, a deodorizing member is provided in the vicinity of the fixing device 11 in FIG. For example, if the deodorizing member is provided between the exhaust fan 16 and the fixing device 11, the deodorizing effect is further enhanced. Further, it is more effective to attach a deodorizing member to each of the fixing device 11 and the exhaust fan 16.

[0017]

As described above, in the image forming apparatus according to the first aspect, since the softening temperatures of the decoloring toner and the normal toner are substantially the same, the fixing conditions are changed between the decoloring toner and the normal toner. Since there is no need to do so, there is no waiting time for changing the fixing conditions, and a complicated mechanism or control means for changing the fixing conditions is unnecessary. In the image forming apparatus of the second aspect, by changing the color of the decoloring toner and the normal toner, it becomes easy to distinguish between the image using the decoloring toner and the image using the normal toner. In the image forming apparatus according to the third aspect, when the decoloring toner and the normal toner have the same color, by marking the recording material on which the image is formed with the decoloring toner, the two can be easily distinguished. As an marking method, an analog type image forming apparatus can use an eraser for marking. Further, as described in claim 4, in the digital type image forming apparatus, marking can be easily performed by outputting image information from the built-in software to form an image.

Further, since the decoloring toner has a poor releasability, it is necessary to apply oil to the fixing roller. However, since the normal toner has a good releasability and does not need to be oil coated, the image forming apparatus according to claim 5. As described above, the cleaning roller or the oil application / cleaning roller is brought into contact with the fixing roller of the fixing device only when the decoloring toner is used. This makes it possible to extend the life of the cleaning roller or the oil application / cleaning roller. Further, although the decoloring toner has a problem of odor, a deodorizing member is provided in the vicinity of the fixing device as in the image forming apparatus of claim 6, and the deodorizing member is provided as in the image forming apparatus of claim 7. This problem can be solved by using an exhaust fan together.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention, in which (a) is a schematic configuration diagram showing an example of an electrophotographic image forming apparatus such as a copying machine, and (b) shows an example of a developing device. It is a schematic block diagram.

FIG. 2 is a schematic configuration diagram showing an example of a fixing device used in the image forming apparatus of the present invention.

FIG. 3 is a diagram showing an example of marking for distinguishing an image formed by decoloring toner, FIG. 3A is an example of marking by a digital image forming apparatus, and FIG. 3B is an analog image forming. It is an example of marking by a device.

[Explanation of symbols]

1 ... Normal toner developing device 2 ... Decoloring toner developing device 3 ... Photosensitive drum 4 ... Charging charger 5 ... Paper feeding cassette 8 ... Transfer charger 9 ... Separation Charger 10 ... Transport unit 11 ... Fixing device 12 ... Cleaning device 13 ... Static eliminator 15 ... Eraser 16 ... Exhaust fan 17 ... Fixing roller 18 ... Pressure roller 19 ... Oil applying roller (or oil applying / cleaning roller) 20 ... Deodorizing member 21 ... Heater

Front page continuation (72) Inventor Hidenori Kawabuchi 1-3-6 Nakamagome, Ota-ku, Tokyo, stock company Ricoh (72) In-house Yasuhiro Kodaira 1-3-6 Nakamagome, Ota-ku, Tokyo stock company In Ricoh

Claims (7)

[Claims] 1. An erasable toner and a non-erasable toner (normal toner)
An image forming apparatus having two or more developing devices using the above, and having a heat roller fixing device, wherein the softening temperatures of the decoloring toner and the normal toner are substantially the same. 2. The image forming apparatus according to claim 1, wherein the decoloring toner and the normal toner are changed in color. 3. The image forming apparatus according to claim 1, wherein when the decoloring toner and the normal toner have the same color, the marking material which can be distinguished from the image by the normal toner on the recording material on which the image is formed by the decoloring toner. An image forming apparatus characterized by: 4. The image forming apparatus according to claim 3, wherein as the marking method, when a digital machine is used, image information is output from built-in software to form an image. 5. The image forming apparatus according to claim 1, wherein a cleaning roller, an oil applying roller, or an oil applying / cleaning roller is brought into contact with the fixing roller of the fixing device only when the decolorizing toner is used. . 6. The image forming apparatus according to claim 1, further comprising a deodorizing member provided near the fixing device. 7. The image forming apparatus according to claim 6, wherein a deodorizing member and an exhaust fan are used together.