JPH05127571A - Image forming device provided with function for regenerating paper - Google Patents

Abstract

PURPOSE:To obtain an image forming device provided with a function for regenerating paper, which can be used both as the image forming device and a decolorizing machine. CONSTITUTION:An upper fixing roller 12u between fixing rollers 12u and 12d opposingly provided up and down is formed of a transparent material such as transparent glass, and a halogen lamp 120 is concentrically housed inside the roller 12u. When a decolorizing mode is selected and the paper P where an image is temporarily formed with decolorizing toner is fed, the lamp 120 is turned on and the paper P is irradiated with white light including near infrared wavelength. By setting the rotating speed of the roller 12u lower than the rotating speed in the case of image forming process, the paper P is irradiated with the white light for much time. Thus, the image temporarily formed is erased and the paper P is regenerated.

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 such as a copying machine, and more specifically, in addition to a normal copying operation, it erases an image on a sheet on which an image is once formed with an erasable toner. The present invention relates to an image forming apparatus having a sheet reproducing function that also has a function as an erasing device that performs the sheet reproducing process.

[0002]

2. Description of the Related Art Recently, decolorizable toners and inks have been developed as recording materials for forming images on recording paper. As this type of decolorizable toner, there are the following ones announced by Showa Denko KK. This decolorizable toner contains at least a decolorizable dye and a binder resin, and is blue when not exposed to light of near infrared wavelength, and white when irradiated with light of near infrared wavelength. Is.

As such a decolorizable dye, an organic boron compound salt of a cyanine dye, and the following compounds can be exemplified.

[0004]

[Chemical 1]

[0005]

[Chemical 2]

[0006]

[Chemical 3]

[0007]

[Chemical 4]

[0008]

[Chemical 5]

The above decolorizable dye has an absorption maximum at a near infrared wavelength, typically 810 to 830 nm, and in particular absorbs light near 820 nm to be decolored and becomes white.

As the binder resin, a resin material conventionally used as a binder resin for electrophotographic toner can be used. For example, polystyrene, polystyrene-butadiene copolymer, styrene-based copolymers such as styrene-acrylic copolymer, polyethylene, polyethylene-vinyl acetate copolymer, ethylene-based copolymers such as polyethylene-vinyl alcohol copolymer, Examples thereof include phenolic resins, epoxy resins, allyl phthalate resins, polyamide resins, polyester resins, maleic acid resins. These compounds may be used alone or in combination of two or more.

When the above-described color erasable toner is used as a recording material for a copying machine, for example, an image once formed is erased by irradiating an erasing light on a misprinted or unnecessary recording paper. Therefore, the recording paper can be reused.

Under these circumstances, the development of a color erasing machine equipped with a color erasing lamp has been recently advanced in parallel with the development of a copying machine using a color erasable toner. As a conventional example of this type of decoloring machine, there is one disclosed by Showa Denko KK.

[0013]

By the way, if both a copying machine and a decoloring machine using a decolorizable toner as a recording material are installed in an office, the floor becomes small and the equipment cost becomes low. It has the drawback of being expensive.

The present invention solves the above-mentioned drawbacks of the prior art. A single sheet can be used as both an image forming apparatus and an erasing machine, and can save space in the office and reduce the equipment cost. An object of the present invention is to provide an image forming apparatus having a reproducing function.

[0015]

SUMMARY OF THE INVENTION An image forming apparatus provided with a sheet reproducing function of the present invention is a sheet reproducing function for erasing an image once formed on a sheet with a decolorizable toner to reproduce the sheet. In the image forming apparatus including the image forming apparatus, the sheet on which the image is once formed with the decolorizable toner is set, and when the decoloring mode is set, the sheet is formed by a pair of upper and lower fixing rollers. And a fixing lamp for irradiating the sheet with light to erase the image when the sheet is conveyed to the position of the fixing device. To be achieved.

Preferably, the fixing lamp is built in at least one of the pair of upper and lower fixing rollers, and the fixing roller containing the fixing lamp is made of a transparent material.

Further, preferably, when the erasing mode is set, the rotation speeds of the pair of upper and lower fixing rollers are set lower than the rotation speed at the time of fixing.

Further, preferably, at the time of fixing, the fixing lamp is turned off when the sheet is passed through the pair of upper and lower fixing rollers.

[0019]

A fixing roller including a fixing lamp formed of a halogen lamp or the like is formed of a transparent material such as transparent glass, and a sheet on which an image is once formed with decolorizable toner is provided opposite the fixing roller. When the fixing lamp is turned on by passing the paper between the fixing roller and the fixing roller, the fixing lamp irradiates the paper with white light including near-infrared wavelength. The erased image is erased. Therefore, the reproduction processing of the paper is thereby performed.

If the rotation speed of the fixing roller at this time is set to be slower than the rotation speed at the time of fixing in the normal copy process, the time for erasing becomes longer by that much, so that the reproduction process is further performed. It can be done reliably.

Further, when the image is formed by using the decolorizable toner, if the fixing lamp is turned off at the time of fixing, the image formed before the fixing is discolored, which may deteriorate the image quality. Absent.

[0022]

EXAMPLES Examples of the present invention will be described below.

FIG. 1 shows the overall construction of a digital copying machine to which the present invention is applied. First, the configuration of this copying machine will be described together with the operation in the image forming process.

Below the platen 1 made of transparent glass, a halogen lamp 20 serving as a light source lamp and a first mirror 2 are provided.
A scanner 2 provided with 1 is disposed so as to be capable of reciprocating in the arrow A direction and the opposite direction. The scanner 2 optically scans a document placed on the document table 1. That is, the light emitted from the halogen lamp 20 to the original is reflected by the original, and then by the first mirror 21 in the direction opposite to the arrow A direction, and the second mirror 23 and the third mirror 24 are reflected.
Are guided to the mirror unit 22 which is vertically opposed.

The mirror unit 22 changes the optical path of the reflected light guided to it in the direction opposite to the arrow A direction. In this way, the reflected light whose optical path has been changed is guided to the ISU substrate 4 via the lens 25. The ISU board 4 converts the reflected light from the original 3 into an electric signal, and supplies the electric signal to the IPU board 5 serving as an image processing unit.

The IPU board 5 processes the data such as the editing, reversing, moving, and enlargement / reduction ratio of the original 3 with electric signals, and performs image processing to generate image data. IPU board 5
The image data generated by is supplied to the laser writing unit 6.

FIG. 2 shows the structure of the laser writing unit 6. This laser writing unit 6 includes an IPU board 5
The laser beam emitted from the laser diode 61 in response to the ON / OFF signal given by the scanner is scanned by the polygon mirror 63 as a laser beam LB of data for one line in the sub-scanning direction of the document, and the laser beam LB is reflected. A basic configuration is adopted in which the lower sheet P (see FIG. 1) is exposed via the mirror 66 and the image data for one line corresponding to the original image is sequentially written on the sheet P.

Explaining the configuration a little now, the emission area of the laser beam emitted from the laser diode 61 is as follows.
A collimator lens 62 for collimating the diffused and emitted laser beam into a cylindrical parallel light is provided. The laser beam collimated by the collimator lens 62 is incident on the mirror surface of the polygon mirror 63 that rotates in the direction of arrow B about the vertical axis, and the laser beam LB is generated by the mirror surface. Subsequently, the laser beam LB is corrected by the fθ lens 64 so that the beam diameter becomes constant. This correction is performed so that the scanning speed of the laser beam LB becomes equal at any position on the paper surface of the paper P.

Subsequently, the corrected laser beam LB is subjected to horizontal tilt correction by the cylindrical lens 65. This tilt correction is performed so that the laser beam LB is always exposed perpendicularly to the paper P, and thus the problem that the laser beam LB is curved can be prevented. The laser beam LB after being subjected to the inclination correction has its optical path converted vertically downward by the reflection mirror 66, and is exposed on the paper P.

In addition, a reflection mirror 67 for reflecting a part of the laser beam LB on the laser detection substrate 68 is disposed outside one end of the reflection mirror 66 in the longitudinal direction. Upon detecting the laser beam LB, the laser detection board 68 feeds back a laser detection signal (RB) to the IPU board 5. The IPU board 5 determines the timing of a horizontal synchronizing signal (HSYNC) for image writing based on the laser detection signal, and the laser diode 6 based on the horizontal synchronizing signal.
The ON / OFF timing of 1 is set.

As shown in FIG. 1, the paper (plain paper) P in the paper feeding cassette 7 is conveyed to the exposure area of the laser beam LB in synchronization with the scanning of the scanner 2. Specifically, this transportation is performed as follows. That is, the rotation of the paper feed roller 8 disposed above the front end of the paper feed cassette 7 feeds the uppermost paper P of the multiple papers P stacked in the paper feed cassette 7 into the machine. .. Subsequently, the paper P is transported to the position of the developing unit 9 arranged on the downstream side of the paper feed cassette 7 (downstream side in the transport direction of the paper P).

The developing unit 9 contains decolorizable toner T (see FIG. 3) made of the material described in the section of the prior art, and the decolorizable toner T is positive in the developing unit 9. Triboelectrically charged to the state. Subsequently, the decolorizable toner T is developed over the entire surface of the paper P by the cooperative action of the developing sleeve 90 in the developing unit 9 and the auxiliary roller 10 provided below the developing sleeve 90. ..

FIG. 3 shows this developing principle. As shown in the figure, the auxiliary belt 10 is grounded, and when a positive developing bias voltage is applied to the developing sleeve 90, the positive decolorizable toner T is developed on the paper P by the bias voltage. It has become so.

On the downstream side of the developing unit 9, there is arranged a conveyor belt 11 for conveying the paper P, on which the decolorizable toner T is entirely developed, toward the downstream side. An exposure area of the laser beam LB is set at an intermediate portion in the longitudinal direction corresponding to the transport direction of the transport belt 11. Therefore, as the sheet P is conveyed to the downstream side, the sheet P is sequentially exposed from the front end side.

When the laser beam LB is exposed, the paper P
Since the exposed part of changes from blue to white,
An image corresponding to the original image is formed on the sheet P. The image area of the paper P may be exposed to the laser beam LB to perform white printing, or conversely, the laser beam LB may be applied to the non-image area.
Alternatively, blue printing may be performed by irradiating.

The sheet P on which the image is formed is the conveyor belt 11
Is continuously conveyed to the downstream side and is supplied to the fixing device 12. As shown in FIG. 4, the fixing device 12 includes a pair of upper and lower fixing rollers 12u and 12d. Of this,
The upper fixing roller 12u is made of a transparent material such as transparent glass, and the halogen lamp 120 is concentrically mounted inside the fixing roller 12u. A thermistor S1 (see FIG. 5) that detects the surface temperature of the fixing roller 12u is arranged outside the fixing roller 12u. The detection signal of the thermistor S1 is given to the CPU 30 shown in FIG.

The fixing device 12 includes upper and lower fixing rollers 12u,
The decolorizable toner T is fixed by pressing and heating the paper P that is passed between the sheets 12d. The paper P that has undergone the fixing process is discharged onto the discharge tray 13.

FIG. 5 shows the structure of a control system for controlling the fixing device 12. A sheet input sensor S2 and a sheet discharge sensor S3 that detect that the sheet P has been conveyed to the upstream and downstream sides of the fixing device 12 in the sheet conveyance direction.
Are respectively arranged. The detection signals of the sheet input sensor S2 and the sheet discharge sensor S3 are given to the CPU 30. CPU3
0 is the center of the control system of this control system, and O of the halogen lamp 120 is used in the above-mentioned image forming process.
N / OFF (lighting) control is performed. Further, in the decoloring mode described later, the rotation speed of the fixing roller 12u is controlled.

First, the halogen lamp 120 is turned on / of
The F control is performed as follows. That is, since the fixing roller 12u is formed of the transparent material as described above,
If the halogen lamp 120 is turned on during fixing, the color-erasable toner may be discolored and the image quality may be deteriorated. Therefore, according to the present invention, when the paper input sensor S2 detects the paper P, the CPU 30 which receives the detection signal from the paper input sensor S2.
Calculates the time when the paper P is caught by the fixing rollers 12u and 12u, and at that time, the lamp ON / OFF circuit 33
Sends a turn-off command signal to. As a result, the halogen lamp 120 is turned off at the time of fixing, and the deterioration of the image quality is prevented.

The lighting control of the halogen lamp 120 before the sheet P is caught by the fixing rollers 12u and 12d is C
PU30 performs according to the temperature detection signal from the thermistor S1. That is, the CPU 30 is supplied with a reference signal for setting the surface temperature of the fixing roller 12u to a predetermined reference temperature, and the CPU 30 uses the reference signal and the temperature detection signal from the thermistor S1 to fix the fixing roller 12u. The halogen lamp 120 is controlled to be turned on so as to set the surface temperature of the sheet to a temperature required for fixing.

When the fixing process is completed, the paper discharge sensor S3 detects the paper P conveyed to this position and gives a detection signal to the CPU 30. Upon receiving the detection signal, the CPU 30 issues a lighting instruction signal to the lamp ON / OFF circuit 33. As a result, the halogen lamp 120 is turned on again.

Next, the erasing mode in which the image once formed with the erasable toner is erased to reproduce the paper P will be described. The paper feed cassette 7 in which a large number of papers P on which images are once formed with decolorizable toner is stored is set in the copying machine main body, and the decoloring mode selection key 32 provided on the operation display panel is turned on by the operator. Then, the CPU 30 determines that the erasing mode is selected,
First, the paper feed roller 8 is driven to drive the paper P in the paper feed cassette 7.
Paper is fed into the machine one by one from the top. The sheet P fed into the machine passes between the developing sleeve 90 and the auxiliary roller 10, and is subsequently conveyed by the conveyor belt 11 toward the downstream side.

In this decoloring mode, the developing bias voltage is not applied to the developing sleeve 90.
That is, as shown in FIG. 5, in this case, the CPU 30
A developing stop command signal is input to the developing unit 9 from the driver 31 via the driver 31, and the developing unit 9 is set to the OFF state. Similarly, the scanner 2 is not driven and the laser writing unit 6 is not operated.

When the transport position of the sheet P transported downstream by the transport belt 11 reaches the position of the sheet input sensor S2,
The paper input sensor S2 detects this and sends a detection signal to the CPU 30.
Give to. The CPU 30 calculates the time when the paper P reaches the fixing device 12 from the detection signal from the paper input sensor S2,
At that time, a deceleration command signal is issued to the drive mechanism 310 via the driver 31, and the rotation speed of the fixing roller 12u is set lower than the rotation speed at the time of fixing. The drive mechanism 310 is composed of a motor, a clutch, and the like. At this time, the halogen lamp 120 is in a lit state.

When the rotation speed of the fixing roller 12u is set to be higher than that at the time of fixing, the conveyance speed of the sheet P which is caught between the fixing rollers 12u and 12d and is conveyed toward the downstream side is reduced, so that it is lengthened accordingly. Since the paper P is illuminated by the halogen lamp 120, the image once formed is erased, that is, the reproduction processing of the paper P is performed more reliably. The decolorized paper P is discharged onto the discharge tray 13.

In the above embodiment, the fixing roller 12u
Is made of a transparent material, and the halogen lamp 120 is
However, the lower fixing roller 12d may be formed of a transparent material and the halogen lamp 120 may be housed therein, and the pair of upper and lower fixing rollers 12u and 12d are both transparent. Alternatively, the halogen lamp 120 may be formed of a material and the halogen lamp 120 may be housed in the interior thereof.

According to the copying machine having the above structure, the image forming process and the regenerating process of the paper P can be performed together. That is, this copier can exhibit the function as a copier and the function as an erasing device by one unit. Therefore, not only the function of the copying machine can be improved, but also the floor space can be saved when the copying machine is installed in an office, and the facility cost can be reduced.

Further, according to this copying machine, devices such as a charger and a photosensitive drum are unnecessary, so that the apparatus configuration is remarkably simplified, miniaturized and lightweight as compared with, for example, an electrophotographic copying machine. There is an advantage that can be realized.

Further, since fixing and erasing can be performed by the same halogen lamp 120, the structure of the fixing device 12 does not become large, and the above advantages can be further exerted. In addition, since the paper passage path of the paper P is the same at the time of erasing and at the time of image formation, in this respect also, the device configuration is simplified,
It can greatly contribute to size reduction and weight reduction.

In the above embodiment, the fixing roller 12u is made of a transparent material, so that the halogen lamp 120 indirectly irradiates the paper P with light through the fixing roller 12u to perform the regeneration processing of the paper P. However, as shown in FIG. 4, when the paper P is conveyed, at that time, the fixing roller 12u is moved in the axial direction indicated by the arrow B, that is, the fixing roller 12u is removed from the halogen lamp 120, and thus the fixing roller 12u is removed. The paper P may be reproduced by directly irradiating the paper P with light from the halogen lamp 120.
In this case, it is not necessary to form the fixing roller 12u with a transparent material.

In the above embodiment, the case where the present invention is applied to a digital copying machine has been described, but the application target of the present invention is not limited to such a copying machine, and a copying machine or printer having a fixing device is provided. The present invention can be widely applied to image forming apparatuses in general.

[0052]

As described above, according to the image forming apparatus having the paper reproducing function of the present invention, it is possible to perform the image forming process and the paper reproducing processing together, and thus it is possible to improve the function of the image forming apparatus. There is. Further, since one copying machine can be used as both the copying machine and the erasing machine, there is an advantage that the floor space can be saved and the equipment cost can be reduced when installing in an office.

[Brief description of drawings]

FIG. 1 is a front sectional view showing the overall configuration of a copying machine to which the present invention is applied.

FIG. 2 is a perspective view showing the configuration of a laser writing unit.

FIG. 3 is a principle explanatory view showing a printing principle of the present invention.

FIG. 4 is a side view showing a schematic configuration of a fixing device.

FIG. 5 is a block diagram showing a control system of the fixing device.

[Explanation of symbols]

 2 Scanner 5 IPU substrate 6 Laser writing unit 61 Laser diode 63 Polygon mirror 66 Reflecting mirror 9 Developing unit 90 Developing sleeve 10 Auxiliary roller 11 Conveyor belt 12 Fixing device 12u Fixing roller 120 Halogen lamp 30 CPU 32 Decoloring mode selection key 33 Lamp ON・ OFF circuit S1 Thermistor S2 Paper input sensor S3 Paper ejection sensor LB Laser beam P Paper T Decolorizable toner

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technology display location G03G 15/22 103 Z 6830-2H (72) Inventor Tetsuya Nakano 1-2 chome Takuzo, Chuo-ku, Osaka No. 28 In Mita Engineering Co., Ltd. (72) Inventor Masai Inoue 1-228 Tamatsukuri, Chuo-ku, Osaka City Mita Engineering Co., Ltd. (72) Inventor Kazuhiko Yamamura 1-228 Tamatsukuri, Chuo-ku, Osaka City Within Mita Engineering Co., Ltd.

Claims (4)

[Claims] 1. An image forming apparatus having a paper reproducing function for erasing an image once formed on a sheet with a color erasable toner and reproducing the sheet, wherein an image is once formed with the color erasable toner. When the sheet is set and the erasing mode is set, the sheet is conveyed to the position of the fixing device, which conveys the sheet to the position of the fixing device formed by a pair of upper and lower fixing rollers. Then, an image forming apparatus having a sheet reproducing function, which comprises a fixing lamp for irradiating the sheet with light to erase the image. 2. The sheet reproducing function according to claim 1, wherein the fixing lamp is built in at least one of the pair of upper and lower fixing rollers, and the fixing roller containing the fixing lamp is made of a transparent material. An image forming apparatus equipped with. 3. The sheet reproducing function according to claim 2, wherein when the erasing mode is set, the rotational speeds of the pair of upper and lower fixing rollers are set to be lower than the rotational speed during fixing. Image forming apparatus. 4. An image forming apparatus having a sheet reproducing function according to claim 2, wherein the fixing lamp is turned off when the sheet is passed through the pair of upper and lower fixing rollers during fixing.