JPH07239636A - Image forming apparatus and image forming system - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide an image forming apparatus and an image forming system capable of preventing illegal copying, printing, and printing. A first mode in which the copying machine 100 performs an image forming process under normal image forming conditions, and a toner is not completely removed from the transfer paper 17 even when the toner removing process is performed by the toner removing device. The second mode in which the image forming process is performed under various image forming conditions is selectable. The linear velocity of the entire copying machine 100 when the second mode is selected is made slower than when the first mode is selected. By doing so, the fixing property of the toner on the transfer paper 17 is improved. As a result, the toner on the transfer paper 17 remains on the transfer paper 17 without being completely removed by the toner removing device. Therefore, an image (toner image) is generated in the second mode.
It is possible to prevent the transfer paper 17 having the marks formed thereon from being abused.

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 and an image forming system such as a copying machine, a facsimile and a printer.

[0002]

2. Description of the Related Art For example, in a copying machine or a printer, recording paper is set in a paper feeding device thereof, and an image is formed on the recording paper upon receiving a copying or print command. With the development of image recording technology, for example, it has become possible to copy a document almost faithfully. For this reason, there is a need for an illegal copy prevention technology for prohibiting copying although copying is prohibited by law such as securities and banknotes. For example, when a document placed on a copying machine is detected as a document to be copied, it is determined whether the detected document is prohibited by law, and the copy is prohibited. It has been proposed that the copying operation be prohibited or that the copied image is not normally formed (see, for example, Japanese Patent Laid-Open No. 2-288468). Also,
There has also been proposed a technique for preventing copying without permission when a manuscript is imprinted with a "secret" or "secret" mark.

On the other hand, from the viewpoint of effective utilization of natural resources, various techniques have been proposed for erasing an image from a recorded recording paper in order to reuse the recording paper used for recording an image. For example, as one using a solvent, JP-A-1-
Japanese Patent Laid-Open No. 101576 discloses a method of removing an image-forming substance in which a sheet having a toner attached thereto is dipped in a soluble solvent of a toner resin and ultrasonic vibration is applied to release the toner dissolved in the solvent from the surface of the sheet. . Further, as a solvent-free one, in JP-A-2-55195, a heat-meltable ink or toner is applied to a printed material having a release agent coated on a support by an electrophotographic method or a thermal transfer method,
Disclosed is a method for removing an image-forming substance, in which an ink peeling body is superposed on the printed body, passed through a heating roller and a pressure roller, cooled, and then the ink peeling body is peeled off so that the ink peeling body adheres to the ink peeling body. ing. In addition, the applicant first
At least one selected from the group consisting of water as a destabilizing agent, an aqueous solution containing a surfactant, an aqueous solution containing a water-soluble polymer, and an aqueous solution containing a surfactant and a water-soluble polymer in the recorded image carrier. A method for removing an image-forming substance is proposed, in which a certain kind of water or aqueous solution is held and a peeling member is interposed, and the image-forming substance is heat-bonded or pressure-bonded to the peeling member to peel it from the image carrier (for example, See Japanese Patent Application No. 4-255916).

[0004]

Here, the image forming substance removing apparatus adopting the image forming substance removing method as described above, for example, removes only the toner on the recording paper.
In an office, after creating a notification document with a word processor and outputting it with a laser printer, a person in charge of printing may put a signature such as a red stamp or a felt-tip pen. This is issued to each department. In some cases, after imprinting, the user may notice an error in the text and discard it. When such a stamped or signed document is processed by the image forming substance removing device, the toner image is removed as described above, but the red ink or the signature remains because it is not formed by the toner. There is a risk that a person who is not the person in charge of issuing the document forms another sentence on the recording sheet on which the stamp or the like is left, thereby creating a so-called unauthorized document.

In another case, when a specific department or institution stamps a receipt date stamp on copy paper, the receipt date may be significant. When such a copy paper is processed by the image forming substance removing device, the receipt date stamp is left because it is not formed with toner. If you copy a document with different content to a recording sheet that has this receipt date stamp by using a copying machine, etc., the new content will be incorrect and it was created on the previous date and was received legitimately. turn into.

Although the above description is limited to the image forming substance removing device, the image erasing device is not limited to the image forming substance removing device, and the image erasing can be performed when another image erasing method for reusing the recording paper is used. Some technologies may misuse information that cannot be erased. In addition, there is a possibility that the information portion that has not been intentionally erased may be misused.

As described above, the current commercial copying machines, printers, and printing machines detect whether the original document should not be copied from the viewpoint of illegal copying, and prohibit copying. There is something that does
It does not matter what kind of image is formed on the recording paper itself, and there is no one that detects whether or not the recording paper itself is used for an illegal purpose.

The present applicant has previously proposed that a toner removing device that can prevent the misuse or misuse of a transfer sheet on which an unremoved image remains, and the misuse of an unremoved image such as a mark or a signature can also be used as a liquid application device. A toner removing device having an identification mark giving unit for giving an identification mark (punch, ◯ mark, etc.) to a transfer paper in which an unremoved image (an image formed by stamping, writing, etc.) is detected after the toner removing unit has performed the toner removing process (Japanese Patent Application No. 5-259270).

However, the transfer paper having an unremoved image such as the above-mentioned mark or signature that can be abused is easily removed of toner by using the toner removing device which does not have the identification mark giving unit as described above. It can be abused.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an image forming apparatus and an image forming system capable of preventing illegal execution of copying, printing, and printing. Is to provide.

[0011]

In order to achieve the above object, the invention of claim 1 is a developing means for forming a toner image on a latent image carrier using toner, and the toner image is transferred. An image forming apparatus for forming an image composed of the toner on the surface of the image carrier, which has a fixing means for fusing the toner image to the image carrier, and forms the image under normal image forming conditions. It is possible to select between a first mode in which the toner is removed and a second mode in which the image is formed under image forming conditions that regulate the removal of the toner in a toner removing device that removes the toner from the surface of the image carrier. It is what

According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the fixing property of the toner image on the image carrier in the second mode is higher than that in the first mode. It is a thing.

According to a third aspect of the invention, in the image forming apparatus according to the second aspect, the fixing means is a heating member, and the toner softened by the heat of the heating member is passing through the image holding member. A pair of pressure contact members that are in pressure contact with each other, and the image carrier conveyance speed in at least the fixing unit in the second mode is made slower than that in the first mode, so that the second mode is used. The fixing property of the toner image on the image carrier is improved as compared with the case of the first mode.

According to a fourth aspect of the present invention, in the image forming apparatus according to the second aspect, the fixing means is a heating member, and the toner softened by heat of the heating member is passing through the image holding member. A pair of pressure contact members that are pressed against each other, and the heating temperature of the heating member in the second mode is set higher than that in the first mode, so that the image carrier in the second mode is The fixing property of the toner image is improved as compared with the case of the first mode.

According to a fifth aspect of the present invention, in the image forming apparatus according to the second aspect, the fixing means is a heating member, and the toner softened by the heat of the heating member is passing through the image holding member. And a nip width of the pressure contact portion of the pair of pressure contact members in the second mode is made larger than that in the first mode. The fixing property of the toner image on the image carrier is improved as compared with the case of the first mode.

According to a sixth aspect of the present invention, in the image forming apparatus according to the second aspect, there is provided a re-conveying unit that conveys the image holding member that has passed through the fixing unit to the fixing unit again. In the second mode, By re-conveying the image carrier to the fixing unit by the re-conveying unit, the fixability of the toner image on the image carrier in the second mode can be improved.
It is characterized in that it is designed to be improved compared to the case of the mode.

According to a seventh aspect of the present invention, in the image forming apparatus according to the first aspect, a plurality of the developing units are provided, the first developing unit is selected in the first mode, and the second mode is selected in the second mode.
Different from the first developing means, the second developing means using toner which is difficult to be removed by the toner removing device is selected.

According to an eighth aspect of the invention, in the image forming apparatus according to the seventh aspect, the average particle diameter of the toner used in the second developing means is smaller than that of the toner used in the first developing means. And its value is in the range of 0.1 to 7.5 μm.

According to a ninth aspect of the present invention, in the image forming apparatus according to the seventh aspect, the toner used in the first developing means has a particle size larger than a gap between fibers forming the image carrier, The toner used for the second developing means is
It is characterized in that the particle size is smaller than the gap between the fibers constituting the image carrier.

According to a tenth aspect of the present invention, in the image forming apparatus according to the first aspect, a second image of a toner-free type is provided separately from the first image forming means of the electrophotographic type using the toner of the developing means. Forming means is provided, and the first mode is
Selecting the first image forming means, the second mode,
It is characterized in that the second image forming means is selected.

According to an eleventh aspect of the present invention, a first image forming apparatus group including at least one image forming apparatus using a dry electrophotographic system, an image forming apparatus using a wet electrophotographic system, or toner is not used. At least one type of image forming apparatus using an image forming method, a second image forming apparatus group consisting of one unit, and the first and second image forming apparatus connected to the first and second image forming apparatus groups. An image forming unit that forms an image output from the forming unit group, and an image forming unit group that outputs one of the first and second image forming unit groups according to a command from the image forming unit. And selecting means for selecting as.

[0022]

According to the invention of claim 1, a first mode for forming the image under normal image forming conditions and an image for restricting the removal of the toner in the toner removing device for removing the toner from the surface of the image carrier. Since the second mode in which the image is formed can be selected depending on the forming conditions, the image formed in the second mode, that is, the toner image, can be completely removed from the image carrier even if the toner removing device is used. Is not removed, and at least a part remains on the image carrier.

According to the second aspect of the invention, in the second mode, the fixability of the toner image on the image carrier is higher than that in the first mode. The formed toner image has a stronger adhesive force to the image carrier than the toner image formed on the image carrier in the first mode. As a result, the toner image is not completely removed from the image carrier even if a toner removing device is used, and at least a part of the toner image remains on the image carrier.

In the third aspect of the invention, the image carrier conveying speed in at least the fixing means in the second mode is set to be slower than that in the first mode. Therefore, for example, the fixing means heats a fixing heater or the like. In the case of having a member and softening the toner by the heat of the heating member to fuse the toner to the image carrier, the toner image formed on the image carrier in the second mode is of the first mode. Compared with the case, the time to receive the heat of the heating member becomes longer. This makes it possible to improve the fixability of the toner to the image carrier without raising the temperature of the heating member.

In the invention of claim 4, the heating temperature of the heating member of the fixing means in the second mode is set higher than that in the first mode. Therefore, for example, the fixing means is a heating member such as a fixing heater. And the toner is softened by the heat of the heating member and fused to the image carrier, the toner image formed on the image carrier in the second mode is in the first mode. Is softened more than. This makes it possible to improve the fixability of the toner to the image carrier.

In the invention of claim 5, the nip width of the pressure contact portion of the pair of pressure contact members of the fixing means in the second mode is made larger than that in the first mode. The toner image formed on the image carrier is
It is pressed against the image carrier by a stronger pressure contact force than in the mode. This makes it possible to improve the fixability of the toner to the image carrier.

In the second aspect of the invention, in the second mode, the image carrier once passing through the fixing means is conveyed again to the fixing means by the re-conveying means, and the toner is fixed on the image holding body.

In the invention of claim 7, the first developing means selects the first developing means, and the second mode differs from the first developing means in that the toner removing device removes the toner. Since the second developing unit using the difficult toner is selected, the developing is performed by the first developing unit in the first mode, and the second developing unit uses the toner difficult to be removed by the toner removing device in the second mode. Development is performed by the second developing means.

In the invention of claim 8 or 9, since the toner having a diameter smaller than that of the toner used in the first developing means is used in the second developing means, the toner constitutes a fiber constituting the image carrier. It is easy to get into the gap between them.

According to the tenth aspect of the invention, in the first mode, the first image forming means is selected, the electrophotographic image forming process using the toner of the developing means is performed, and the second image forming means is used.
In the mode, the second image forming unit is selected and the image forming process of a method using no toner is performed.

In the eleventh aspect of the present invention, the image created by the image creating means is output from either one of the first and second image forming apparatus groups selected by the selecting means. Here, the image on the image carrier output from the first image forming apparatus group is formed by a dry electrophotographic method. The image output from the second image forming apparatus group on the image carrier is formed by an image forming apparatus using a wet electrophotographic method or an image forming method using no toner. (Hereafter, margin)

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a digital copying machine (hereinafter referred to as copying machine) which is an image forming apparatus will be described below. FIG. 1 is a schematic configuration diagram of a copying machine according to this embodiment. The reading device 1 forms an image of an original (not shown) on a pressure plate provided on the upper part of the copying machine 100 on the CCD 5 through the light source 2, the mirror group 3 and the lens 4, and reads the image information of the original. , Convert to electrical image information.

The writing device 6 irradiates a laser beam from the optical writing part (LD) 7 based on the image signal from the reading device 1, and passes through the polygon mirror 8, the lens 9 and the mirror 10 a photosensitive body line by line. Write a latent image in 11. The photoconductor 11 is uniformly charged in advance by the charging device 12 before the latent image writing process.

The latent image on the photoconductor 11 is developed by the developing devices 13 and 1.
4 visualizes as a toner image. After that, the toner image is preliminarily conveyed from the paper feeding unit 15 and stands by at the position of the registration roller 16, and is transferred by the transfer device 18 onto the transfer paper 17 which is conveyed in time with the latent image.

When the transfer paper 17 on which the toner image is transferred is conveyed by a conveyor belt 19 and passes through a pressure contact portion (hereinafter referred to as a nip portion) 201 between a heating roller 21 having a heater 20 built therein and a pressure roller 22. The toner image is fixed on the surface and then discharged. Here, a thermistor 25 as a temperature detecting means is provided above the heating roller 21 in the figure so as to be in contact with the surface of the heating roller 21 or in the vicinity of the surface in a non-contact state. ing.

After the toner image has been transferred onto the transfer paper 17, the cleaning device 23 removes the toner remaining on the surface of the photoconductor 11 and the charge removing device 24 removes the residual electric charge, so that the next image is formed. Be prepared for.

Further, in the copying machine 100 shown in the figure, a re-conveyance path 26 for conveying the transfer paper 17 that has passed through the nip portion 201 between the heating roller 21 and the pressure roller 22 to the position of the registration roller 16 again is provided. Has been.

By the way, in the case of the transfer paper 17 on which the toner image is formed under the normal image forming conditions in the copying machine 100 having the above-mentioned structure, for example, water as the destabilizing agent, the surface active agent are added to the transfer paper 17. Holding at least one kind of water or aqueous solution selected from the group consisting of an aqueous solution containing an agent, an aqueous solution containing a water-soluble polymer, and an aqueous solution containing a surfactant and a water-soluble polymer, and interposing a peeling member,
The toner is heat-bonded or pressure-bonded to the peeling member,
It may be inconvenient if the toner is completely removed from the transfer paper 17 by using a toner removing device that uses a toner removing method for separating the transfer paper 17. For example, if a normal copy, which is stamped with the red print of the person in charge of issuing the document, is applied to the toner removing device, only the stamped portion remains. Similarly,
If the signature (signature) of the person in charge is written at the end of the English letter with something other than toner, such as a felt-tip pen or ball-point pen, only the signature (signature) remains. It is conceivable to set such a sheet as a transfer sheet in the sheet feeding section 15 and make a copy. If it is done in good faith, an extra seal or signature will be present during copying on the copying machine, resulting in a so-called miscopy. Malicious acts may result in the use of a seal or signature without the knowledge of the person responsible for issuing the document.

Therefore, the copying machine 100 of the present embodiment employs a structure for preventing the transfer paper on which an image including such a marking or signature is formed from being used in the copying machine or the like. . That is, the copying machine 100 according to the present embodiment is
The first mode in which the image forming process is performed under normal image forming conditions, and the image forming condition under which the toner is not completely removed from the transfer paper 17 even when the toner removing process is performed by the toner removing device The operator selects the second mode for performing the processing, and the image forming processing can be performed in the selected mode.

The copying machine 100 according to this embodiment is provided with the operation display section 30 as shown in FIG. 2, and the operation section 30a of the operation display section 30 (see FIG. 2C) is provided. , Mode selection keys 31a, 31 as mode switching means for selecting the first mode and the second mode
b is provided. In addition, the operation unit 3 of the operation display unit 30
0a is a mode display LED 32 as a display means of the mode selected by the mode selection keys 31a and 31b.
a and 32b are provided. Further, a display panel section 30b (see FIG. 2B) of the operation display section 30 is provided with a mode display panel 32c as a mode display means. In the present embodiment, the mode selection key 31
The mode selected by a and 31b is displayed on the operation display unit 3
It may also be displayed on the touch panel LCD unit 30c of 0 (see FIG. 2A).

In the above configuration, when the transfer paper 17 is to be stamped or signed later, and it is desired to form an image (toner image) on the transfer paper 17 which is inconvenient when the toner is completely removed by the toner removing device. The operator presses the mode selection key 31b to set the second mode, and confirms it by the mode display means.

In the present embodiment, push switches are used as the mode selection keys 31a and 31b, but other types may be used. Further, as will be described later, the reading device 1, the writing device 6 or the developing devices 13, 14
In the case where the first mode and the second mode are achieved by changing the image forming conditions, the operating lever or the like is provided in the vicinity of each device, and the operator operates the lever or the like to operate the mechanism. Alternatively, the image forming conditions of the individual devices may be changed. In this case, the mode display means may have the same structure as that described above, but the mode display means may be installed near the lever or the like.

Further, in the case where the copying machine 100 shown in the figure is constructed so as to be used as a printer capable of printing an image or a sentence created by an image creating apparatus such as a personal computer or a word processor, FIG. As shown, the copying machine 100 is connected to the controller 101 and the cable 10.
It is also possible to connect to the image creating apparatus 103 such as a personal computer or a word processor via the device 2. In the case of printing an image or a sentence created by the image creating apparatus 103 with this configuration using the copying machine 100,
As shown in FIG. 4, after the image creating apparatus 103 creates an image or a sentence (step 1), the image creating apparatus 103 selects a mode (step 2) and issues a print command (step 3). The controller 101 determines the mode,
The image forming condition of the copying machine 100 is changed to the image forming condition suitable for the mode (step 4). The copying machine 100 performs the image forming process under the image forming condition of the mode determined in step 4 (steps 5 and 6).

Next, a method for achieving the first mode and the second mode in the present embodiment will be described. As a method of achieving the first mode and the second mode in the present embodiment, first, the fixing device 2 including the heating roller 21 and the pressure roller 22 when the second mode is selected.
00 linear velocity (that is, the transfer paper 1 in the fixing device 200)
7), or the linear velocity of the entire copying machine 100 (that is, the conveyance speed of the transfer paper 17 in the copying machine 100).
Can be slowed compared to when the first mode is selected.

Here, in the fixing device 200, the following formula is established. Q: Amount of heat in the fixing device 200 α: Constant δ: Nip portion 2 between the heating roller 21 and the pressure roller 22
Nip width at 01 v: linear velocity Tr: fixing temperature T ₀ : toner temperature

In the copying machine 100 according to this embodiment, the copying machine 100 when the second mode is selected.
The overall linear velocity is set to be slower than when the first mode is selected. As a result, the rotational speed of the main body drive motor (not shown) and the rotation of the polygon motor for driving the polygon mirror 8 are rotated. And the light emission period of the optical writing unit (LD) 7 are synchronously delayed. Further, the copying machine 10
When 0 does not have an image memory, the rotation speed of the motor for driving the reading device 1 and the reading cycle are also delayed.

In the copying machine 100 according to the present embodiment, the linear velocity of the fixing device 200 when the second mode is selected is set to be slower than when the first mode is selected. In that case, the fixing device 200 may be provided with an independent drive source (motor) or the fixing device 200 (heating roller 2
It is necessary to provide a driving speed switching means (for example, an irregular gear and a clutch) for the heat roller 21 and the pressure roller 22. The distance to the nip portion 201 between and is longer than the length of the transfer paper 17 in the transport direction, and a transport means (suction belt or the like) between them is required.

That is, when the linear velocity of the entire copying machine 100 in the case where the second mode is selected as described above is set to be slower than that in the case where the first mode is selected, Since v is small, Q is large, and the fixing property of the toner on the transfer paper 17 is improved. This allows
The toner on the transfer paper 17 on which the image (toner image) is formed in the second mode is difficult to be removed by the toner removing device, and is not completely removed from the transfer paper 17 and remains on the transfer paper 17. To do. Therefore, it is possible to prevent the transfer paper 17 on which the image (toner image) is formed in the second mode from being abused.

As another method, the fixing temperature (heating heater 20 temperature) in the fixing device 200 when the second mode is selected is set higher than that when the first mode is selected. It can be mentioned.

When this method is adopted, when the second mode is selected, the controller 40 (see FIG. 1) causes the thermistor 2 to operate.
On receiving the temperature data from 5, the on / off control temperature of the heater 20 is set to a temperature higher than that in the first mode.

In this way, when the fixing temperature (heating heater 20 temperature) in the fixing device 200 when the second mode is selected is set to be higher than when the first mode is selected, Since Tr in the above equation becomes large,
Q is increased, and the fixing property of the toner on the transfer paper 17 is improved.

In this example, the heating roller 2 is used.
5, a fixing device having a heating member 204 including a film member 202 formed into a roll shape as shown in FIG. 5 and a sheet heating element 203 provided inside the roll film member 202. Also in the case of using 200a, similarly to the above, temperature control is performed by a thermistor (not shown) provided integrally with the sheet heating element 203, and fixing in the fixing device 200a when the second mode is selected. The temperature (the temperature of the sheet heating element 203) may be set higher than when the first mode is selected.

As another method, the nip width at the nip portion 201 between the heating roller 21 and the pressure roller 22 of the fixing device 200 when the second mode is selected,
It may be set to be larger than that when the first mode is selected.

Here, in the fixing device 200 of the copying machine 100 according to the present embodiment, the pressure roller 22 is rotatable by the support member 206 biased upward by the pressure spring 205 as shown in FIG. Supported by. The pressure roller 22 is pressed against the heating roller 21 by the support member 206 that is urged upward by the pressure spring 205 to form the nip portion 201.

In the fixing device 200 having the above structure,
When the second mode is selected, the control unit 40 (see FIG. 1)
Drives a solenoid (not shown) that pulls the pressure spring 205 upward. The pressure spring 205 is pulled upward by driving the solenoid, and the supporting member 2
06 is pulled upward, the pressure roller 22 comes into pressure contact with the heating roller 21 with a stronger pressure contact force, and the nip width a in the nip portion 201 increases.

When the nip width a at the nip portion 201 with the pressure roller 22 in the case where the second mode is selected is set to be larger than that in the case where the first mode is selected , Δ in the above equation increases, so Q
Becomes larger, and the fixing property of the toner on the transfer paper 17 is improved.

In the case of this example, a compression spring or a torsion coil spring may be used instead of the pressure spring 205. Further, a pressure lever for pulling up the pressure spring 205 and the support member 206 is provided, and when the second mode is selected, the operator operates the pressure lever to heat the pressure roller 22. The pressure applied to 21 may be increased. In the case of such a configuration, the cost can be suppressed because the control and the configuration are simplified. In addition, the roll-shaped film member 202 and the sheet heating element 2 as shown in FIG.
Similarly, in the fixing device 200a having the heating member 204 composed of 03, the spring used for pressing the pressure roller 22 against the heating member 204 is pulled upward to apply the pressure roller 22 to the heating member 204. The nip width a in the nip portion 201 may be increased by increasing the pressure.

As another method, when the second mode is selected, the transfer paper 17 that has once passed through the fixing device 200 and has undergone the fixing process is conveyed again to the fixing device 200 and the fixing process is performed. It is possible to give it.

When this method is used, when the second mode is selected, the transfer paper 17 that has undergone the first fixing process is
As shown in FIG. 1, the sheet is sent to the re-conveyance path 26 provided in the main body of the copying machine 100 and conveyed through the re-conveyance path 26.
The image forming surface is heated by the heating roller 21 as in the case of the fixing process of the second time.
The sheet is re-conveyed to the fixing device 200 in a state of facing the side. Here, at the time of the second conveyance, the transfer paper 17 is controlled not to form an image but to perform only the fixing process. Then, the transfer paper 17 that has undergone the second fixing process is ejected, but if necessary, the fixing device 200 is re-executed in the same flow as described above.
It may be configured to be transported to.

In the present example, the path for re-transferring the transfer paper 17 is not necessarily limited to the re-transfer path 26 shown in the figure. For example, the transfer paper 17 may be once discharged to the discharge tray and then transferred to the fixing device 200 again. Good, copier 1
It is also possible to provide an intermediate tray inside the main body of 00 to store the transfer paper 17 after the first fixing process once in the intermediate tray and then convey it to the fixing device 200 again.
Further, for example, in an image forming apparatus that has a re-conveyance path in advance for performing double-sided image formation or a composite image formation such as a color copying machine, if the re-conveyance path is used, a special re-conveyance path is used. It is not necessary to provide a transportation route.

As another method, when the second mode is selected, a developing device different from the developing device used during normal image formation is used.

Here, in the copying machine 100 according to the present embodiment, the two developing devices 13 and 14 are provided as described above. For example, the developing device 13 has an average particle size of 7.5.
Toner larger than μm is stored in the developing device 1.
Toner 4 is smaller than the toner of the developing device 13 and has an average particle diameter of 0.1 to 7.5 μm. Then, during the normal image forming processing (when forming an image that may be removed by the toner removing device), the developing device 13 is used for development. When the second mode is selected, the developing device 13 is used for developing.

When the second mode is selected as described above, when developing is performed using a toner having a small diameter, the toner enters between the fibers constituting the transfer paper 17 and is fixed to the transfer paper 17. Sex improves.

In this example, when the second mode is selected, it is desirable to switch the image forming process conditions so that a better image can be formed. The switching between the two developing devices 13 and 14 may be performed by the control unit 40 by selecting a mode with the mode selection keys 31a and 31b of the operation unit 30a.
A switching lever or the like may be provided and the operator may operate the lever.

As another method, for example, the developing device 13 contains a toner which is not dissolved in hot water,
When the first mode is selected, the developing device 13 is used for development, and the developing device 14 contains toner having a coloring component that dissolves in hot water. When is selected, the developing device 14 is used to perform the development.

Here, the toner that does not dissolve in hot water may have the same material as that of a normal toner except for the solubility in water. Examples of the charge control agent include quaternary ammonium salts, salicylic acid derivatives and phenol compounds.

As the binder resin used in the toner that does not dissolve in hot water in this example, those which have been used as the binder resin for toner so far can be basically applied. Specifically, homopolymers of styrene such as polystyrene, polychloroethylene, and polyvinyltoluene, and their substitution products; styrene-P-chlorostyrene copolymer, styrene-
Propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-
Methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer Coalesce, styrene-butyl methacrylate copolymer,
Styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer Polymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-
Styrene-based copolymers such as maleic acid ester copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, polyvinyl butyl butyral, rosin, modified rosin, terpene resin, phenol Examples thereof include resins, aliphatic or alicyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffins and paraffin waxes, which may be used alone or in combination of two or more.

The pigments and dyes used in the toner which is not soluble in hot water in this example are the pigments conventionally used,
All of dyes and polarity control agents can be applied. Specifically, ultramarine, nigrosine dye, aniline blue, chalco oil blue, DuPont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, phthalocyanine green, rhodamine 6C lake, quinacridone, benzidine yellow, malakanaide green, hansa yellow G, Malachide green hexalate, oil black, azo oil black, rose bengal, monoazo dyes and pigments, disazo dyes and pigments, trisazo dyes and pigments, quaternary ammonium salts, metal salts of salicylic acid and salicylic acid derivatives, and mixtures thereof. To be It goes without saying that attention should be paid to the solubility in water or hot water.

A releasing agent may be contained in the toner that does not dissolve in hot water in this example. As the release agent, in addition to synthetic waxes such as low molecular weight polyethylene and polypropylene,
Candelilla wax, carnauba wax, rice wax, tree wax, jojoba oil and other plant waxes, beeswax, lanolin, whale wax and other animal waxes, montan wax, ozokerite and other mineral waxes,
Examples include oil-based waxes such as hydrogenated castor oil, hydroxystearic acid, fatty acid amide, and phenol fatty acid ester. In addition to the above components, the toner of the present invention contains various plasticizers (dibutyl phthalate, dioctyl phthalate, etc.), resistance, etc. for the purpose of adjusting the thermal properties, electrical properties, physical properties, etc. of the toner as necessary. It is also possible to add auxiliary agents such as regulators (tin oxide, lead oxide, antimony oxide, etc.).

If desired, the toner insoluble in the hot water of this embodiment may be mixed with additives other than the toner resin and the colorant. Examples of the additive include a fluidizing member such as colloidal silica, titanium oxide, and aluminum oxide. It is preferable that the fluidizing agent has a primary particle size smaller than 0.1 μm, and the surface thereof is subjected to a hydrophobic treatment with a silane coupling agent, silicone oil or the like.

When this method is adopted, when the second mode is selected, the developing device 14 is used to perform the development. Then, for example, at least one selected from the group consisting of water as a destabilizing agent for the transfer paper 17, an aqueous solution containing a surfactant, an aqueous solution containing a water-soluble polymer, and an aqueous solution containing a surfactant and a water-soluble polymer. A toner removing device using a toner removing method of holding one kind of water or an aqueous solution and interposing a peeling member, heat-bonding or pressure-bonding toner to the peeling member, and peeling the toner from the transfer paper 17 is used. Then, when an attempt is made to remove the toner from the transfer paper 17 on the surface of which the image developed by the developing device 14 has been formed, the toner has a coloring component that dissolves in hot water. The material begins to melt, and a colored residual image is formed on the transfer paper 17 along the toner image. As a result, it is possible to prevent the transfer paper 17 on which the image (toner image) is formed in the second mode from being abused.

Also in this example, when the second mode is selected, it is desirable to switch the image forming process conditions so that a better image can be formed.
Further, the switching between the two developing devices 13 and 14 may be performed by the control unit 40 by selecting a mode by the mode selection keys 31a and 31b of the operation unit 30a, or by providing a switching lever or the like, The operation may be performed by an operator.

As another method, when the second mode is selected, an image forming means different from the image forming means used in the first mode is selected, and the image forming means is selected. The image forming process may be performed in the above.

FIG. 7 is a view showing the schematic arrangement of the copying machine 100a according to this example. In the illustrated copying machine 100a,
In addition to the first image forming means 50a including the writing device 6, the photoconductor 11, the charging device 12, the developing device 13, the transfer device 18, the cleaning device 23, and the charge removing device 24,
A second image forming unit 50b is provided which includes a thermal transfer ribbon 51, a heating element 52, a thermal transfer ribbon 51, and a facing roller 53 which is disposed so as to face the heating element 52 with the conveyor belt 19 interposed therebetween. . Copier 1 according to this configuration
In 00a, when the second mode is selected, the second mode is selected.
Image forming processing is performed by the image forming means 50b. By doing so, the image on the transfer paper 17 that has been subjected to the image forming processing by the second image forming unit 50b cannot be removed from the transfer paper 17 even by using the toner removing device, and thus the second image is formed. Transfer paper 1 with an image formed in the mode
It can be prevented that 7 is misused. (Hereafter, margin)

In this example, as the second image forming means 50b, an ink jet type image forming means having a structure in which a solution containing a pigment is directly jetted onto the transfer paper 17 or a dot impact type image forming means using an ink ribbon is used. Image means or the like may be used. Further, switching between the two image forming means 50a and 50b is performed by switching the mode selection keys 31a and 3 of the operation unit 30a.
It may be performed by the control unit 40 by selecting the mode by 1b, or may be performed by providing a switching lever or the like and operating the lever by an operator.

By the way, an image that can be completely removed by the toner removing device or an image that cannot be completely removed by the toner removing device as described above can also be formed by an image forming system having the following configuration. Is. That is, FIG.
Is a first printer group 60 using a dry electrophotographic method
And a second printer group 61 using an inkjet method, a thermal transfer method using thermal paper, a dot impact method or a wet electrophotographic method, and a document / image (image data such as a personal computer, a word processor or a facsimile). ) Creating means 62, the first printer group 60 and the second printer group 61, and the document / image creating means 62 are connected to each other by, for example, a data line, and based on signals from the document / image creating means 62. FIG. 3 is a diagram showing an image forming system including a selection unit 63 such as a printer buffer for selecting (switching) a printer group to be output (printed).

In such an image forming system,
The document / image creating means 62 creates a document / image,
When the image erasure prohibition mode is selected when the output command is issued, the selection unit 63 selects the second printer group 61 as the printer group to output (print), and transfers the data to the second printer group 61. Then, the second printer group 61 performs an image forming process based on the data. The image formed in this way is an image that cannot be removed by a toner removal device such as the inkjet system, the thermal transfer system using thermal paper, the dot impact system, or the wet electrophotographic system as described above. Even if the device is used, it cannot be removed from the transfer paper 17, and thus the transfer paper 17 can be prevented from being abused.

As described above, according to the present embodiment, the image is formed on the transfer paper 17 under the image forming condition in which the fixing property of the toner on the transfer paper 17 is improved, so that the transfer paper 17 can be formed on the transfer paper 17 even after the toner removing process. To allow the toner to remain,
By forming an image on the transfer paper 17 by using a toner that dissolves in hot water and colors the transfer paper 17, it is possible to form a colored residual image on the transfer paper 17 after the toner removal processing or to remove the toner. Since an image is formed on the transfer paper 17 by an image forming unit that does not use toner that can be removed by the apparatus, the image remains on the transfer paper 17 even after the toner removal processing. Even if there is a marking portion or a signature portion remaining on the paper 17 even after being applied to the toner removing device, it is possible to prevent the transfer paper 17 from being abused.

In the present embodiment, a digital copying machine was described as an example of an image forming apparatus to which the present invention is applied, but the present invention is also applicable to an image forming apparatus such as an analog copying machine, a laser printer, a facsimile. Applicable.
Further, in the copying machine of the embodiment according to FIGS. 1 to 8 above, normally, the first mode is selected, and after the second mode is selected and a series of image forming processing is completed, the first mode is automatically set. It is effective to prevent a mistake in operation by providing a function to recover the data. Further, in the embodiments according to FIGS. 1 to 8 described above, the copying machine having the drum-shaped photoconductor 11 has been described as an example, but a copy having, for example, a belt-shaped photoconductor instead of the drum-shaped photoconductor 11. It may be a machine.

[0080]

According to the first aspect of the present invention, the image formed in the second mode, that is, the toner image is not completely removed from the image carrier even when the toner removing device is used, and the image is not completely removed. Since at least a part of the image carrier remains on the carrier, it becomes difficult to reuse the image carrier.
It is possible to prevent a new image from being written and abused.

According to the second aspect of the present invention, the second mode can be realized without changing the structure of the image forming apparatus itself, only by changing the control condition of the apparatus.

According to the third aspect of the present invention, for example, even when the fixing unit has a heating member and the toner is softened by the heat of the heating member to be fused to the image carrier, Since it is possible to improve the fixing property of the toner to the image holding member without raising the temperature, it is possible to prevent the power consumption and the in-machine temperature from rising.

According to the invention of claim 4, by raising the heating temperature of the heating member of the fixing means, it becomes possible to improve the fixability of the toner to the image holding member, thus sacrificing the productivity. It is possible to improve the fixing property without any. That is, when the image carrier conveying speed in the fixing unit is slowed as in the third aspect, the fixing property can be improved, but the number of image forming processes that can be executed per unit time is reduced. However, in the invention of claim 4, since the fixing property can be improved and the image carrier conveying speed is not slowed as described above, the number of image forming processes that can be executed per unit time is small. It never happens. Thereby, the image on the image carrier cannot be easily removed even by using the toner removing device.

According to the invention of claim 5, the image carrier carrying speed in the fixing means is slowed down as in claim 3 or the heating temperature of the heating member is raised as in claim 4. However, by increasing the nip width of the pressure contact portion of the pair of pressure contact members, it is possible to improve the fixability of the toner to the image holding member, it is possible to prevent the power consumption and the temperature inside the machine from rising, and There is no sacrifice in productivity.

According to the sixth aspect of the present invention, in the second mode, the image carrier which has once passed through the fixing means is conveyed again to the fixing means by the re-conveying means, and the toner is fixed on the image holding body. Therefore, it becomes possible to improve the fixability of the toner to the image carrier. Thereby, the image on the image carrier cannot be easily removed even by using the toner removing device.

According to the invention of claim 7, in the second mode, unlike the first developing means, the second developing means using the toner that is difficult to be removed by the toner removing device is selected and the development is performed. By using a toner having excellent fixability as the toner, the fixability of the toner to the image carrier can be improved. Thereby, the image on the image carrier cannot be easily removed even by using the toner removing device.

According to the invention of claim 8 or 9,
The toner used in the developing unit of 1) is more likely to enter the gap between the fibers forming the image holding member than the toner used in the first developing unit, so that the fixing property of the toner to the image holding member can be improved. Become. Thereby, the image on the image carrier cannot be easily removed even by using the toner removing device.

According to the tenth aspect of the present invention, since the second image forming means is selected in the second mode and the image forming process of a method using no toner is performed, the image is formed in the second mode. The image on the image carrier is not removed even by using the toner removing device, and it is possible to prevent misuse of the image carrier having an image that cannot be removed, such as a mark or a signature.

According to the eleventh aspect of the present invention, the second image forming apparatus group is selected according to the instruction of the operator, and the image output from the second image forming apparatus group is the wet type electronic image. Since the image is formed by the image forming apparatus using a photographic method or the image forming method that does not use toner, it cannot be removed by the toner removing device. It can be formed on a holder. Further, since the image on the image carrier output from the second image forming apparatus group cannot be removed even by using the toner removing device, an unremovable image such as a mark or a signature is formed on the image carrier. Even in some cases, abuse of the image carrier can be prevented.

[Brief description of drawings]

FIG. 1 is a front view showing a schematic configuration of a copying machine according to an embodiment.

FIG. 2A is a schematic configuration diagram of an operation display unit of the copying machine.
(B) is a schematic block diagram of a display panel section of the operation display section.
(C) is a schematic block diagram of the operation part of the operation display part.

FIG. 3 is an explanatory diagram showing a connection example between the image forming apparatus and the copying machine.

FIG. 4 is a flowchart showing the flow of processing in this embodiment.

FIG. 5 is a schematic configuration diagram of a fixing device according to another configuration.

FIG. 6 is a schematic configuration diagram of a fixing device of the copying machine.

FIG. 7 is a schematic configuration diagram of a copying machine according to another configuration.

FIG. 8 is a schematic configuration diagram of an image forming system according to the present embodiment.

[Explanation of symbols]

 1 Reading Device 2 Light Source 3 Mirror Group 4 Lens 5 CCD 6 Writing Device 7 Optical Writing Unit (LD) 8 Polygon Mirror 9 Lens 10 Mirror 11 Photoreceptor 12 Charging Device 13 Developing Device 14 Developing Device 15 Paper Feeding Unit 16 Registration Roller 17 Transfer paper 18 Transfer device 19 Conveyor belt 20 Heating heater 21 Heating roller 22 Pressure roller 23 Cleaning device 24 Static eliminator 25 Thermistor 26 Re-conveyance path 40 Control unit 100 Copier

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Toshio Uehara 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd.

Claims (11)

[Claims] 1. A developing means for forming a toner image on a latent image carrier using toner, and a fixing means for fusing the toner image to an image carrier to which the toner image has been transferred. An image forming apparatus for forming an image of the toner on the surface of the image carrier, a first mode for forming the image under normal image forming conditions, and a toner removing device for removing the toner from the surface of the image carrier. The image forming apparatus is characterized in that a second mode for forming the image can be selected under image forming conditions that regulate the removal of the toner. 2. The image forming apparatus according to claim 1, wherein in the second mode, the fixability of the toner image on the image carrier is higher than that in the first mode. 3. The fixing means comprises a heating member and a pair of pressure contact members for contacting the toner softened by the heat of the heating member with the image holding member passing through the pressure contact portion. In the second mode, at least the image carrier carrying speed in the fixing means is set to be slower than that in the first mode, so that the fixability of the toner image to the image carrier in the second mode is improved. The image forming apparatus according to claim 2, wherein the image forming apparatus is improved as compared with the case of the mode. 4. The fixing means comprises a heating member and a pair of pressure contact members for contacting the toner softened by the heat of the heating member with the image carrier passing through the pressure contact portion. By setting the heating temperature of the heating member in the second mode higher than that in the first mode, the fixing property of the toner image on the image carrier in the second mode is increased in the first mode. The image forming apparatus according to claim 2, wherein the image forming apparatus is improved as compared with the image forming apparatus. 5. The fixing means comprises a heating member and a pair of pressure contact members for contacting the toner softened by the heat of the heating member with the image carrier passing through the pressure contact portion. By making the nip width of the pressure contact portion of the pair of pressure contact members in the second mode larger than that in the first mode, the fixability of the toner image to the image carrier in the second mode can be improved. The image forming apparatus according to claim 2, wherein the image forming apparatus is improved as compared with the case of the mode 1. 6. Re-conveying means for conveying the image holding body having passed through the fixing means to the fixing means again, and in the second mode, the image holding body is again conveyed to the fixing means by the re-conveying means. By conveying the toner image, the fixing property of the toner image on the image holding member in the second mode is improved.
The image forming apparatus according to claim 2, wherein the image forming apparatus is improved as compared with the case of the mode. 7. A plurality of the developing means are provided, the first developing means is selected as the first mode, and the second mode is selected as the second mode.
2. The image forming apparatus according to claim 1, wherein, unlike the first developing unit, a second developing unit that uses toner that is difficult to remove by the toner removing device is selected. 8. The average particle size of the toner used in the second developing means is smaller than that of the toner used in the first developing means, and the value is in the range of 0.1 to 7.5 μm. The image forming apparatus according to claim 7, wherein 9. The toner used in the first developing means has a particle size larger than the gap between the fibers forming the image carrier, and the toner used in the second developing means is:
8. The image forming apparatus according to claim 7, wherein the particle size is smaller than the gap between the fibers forming the image carrier. 10. A toner-free second image forming means is provided separately from the electrophotographic first image forming means using toner of the developing means, and the first mode is
Selecting the first image forming means, the second mode,
The image forming apparatus according to claim 1, wherein the second image forming unit is selected. 11. At least one using a dry electrophotographic method.
A first image forming apparatus group consisting of one image forming apparatus, and at least one kind of image forming apparatus using a wet electrophotographic method or an image forming apparatus using a toner-free image forming method. Two image forming apparatus groups, an image creating unit that is connected to the first and second image forming apparatus groups and creates an image output from the first and second image forming apparatus groups, and the image creating unit An image forming system, comprising: selecting means for selecting one of the first and second image forming apparatus groups as an image forming apparatus group for outputting the image in response to a command from the means.