JP5581994B2 - Erasing device - Google Patents

Description

  The present invention relates to a decoloring apparatus, and more particularly to a decoloring apparatus mounted on, for example, a rewritable printer.

  In recent years, there has been a call for saving paper resources as part of global environmental protection. In the saving and reuse of paper resources such as image forming apparatuses, effective use of the back side of paper that has been printed on one side is already common in society. In general, the used paper is collected and used as a raw material of the paper and reused as recycled paper.

  However, when reusing paper for single-sided printing, the number of reuse is usually limited to one. In addition, when the material is reused as a raw material, energy and cost are required for the recovery itself, and energy is also applied when processing the raw material.

  Therefore, various efforts have been made to make it possible to use paper multiple times in the office. In order to reuse paper once formed with toner images as paper resources, the image on the paper formed with toner may be physically removed or decolored with light to make the paper reusable. It is considered.

  In order to physically remove the image and reuse the paper, a processing solution for removing the toner is applied to the image forming surface of the paper and heated to dissolve the toner to remove the image. There are methods such as polishing the image forming surface and scraping off the toner image. However, these methods are troublesome because they are troublesome and the paper to be reused is easily damaged.

  Further, for example, as a decoloring method using light, when an image is first formed on a sheet, the image is recorded on an OA sheet with a decoloring toner containing a near-infrared absorbing dye and a decoloring agent, and this image is recorded in the near-field. The idea of reusing paper by erasing light with a special light source such as infrared rays has already been published in a paper. (For example, refer nonpatent literature 1.)

  In the method of Non-Patent Document 1, the near-infrared absorbing dye absorbs excited near-infrared light, excites it, and reacts with a decoloring agent to make it colorless. However, since the coloring material is converted into a toner, the dye in the toner binder resin hardly shows a decoloring reaction at room temperature even when absorbing near infrared rays.

  For this reason, the general method effective for the decoloring effect | action of applying colorless heat and accelerating | stimulating reaction is performed. For example, if the fixing device for image formation and the erasing device for erasing are used in common, and the toner image is erased, the toner image is heated in advance and then the erasing light is irradiated, so that the erasing effect works effectively. Based on the commonly used technology, the heat roller pair of the fixing device used at the time of image formation is also used as a heater at the time of decoloring, and a light source for erasing the decoloring light is provided downstream of the heat roller pair in the fixing device. Arranged configurations have been proposed. (For example, refer to Patent Document 1.)

JP 07-096434 A

Kiichi Hosoda, "Application of functional dyes to toner", Journal of Electrophotographic Society, No. 31

  However, in the prior art disclosed in Patent Document 1, in addition to the problem that the temperature of the toner image is lowered before the toner image heated by the heating roller is irradiated with the decoloring light, the decoloring effect is reduced. In addition, the problem that the toner image is offset remains as a problem to be solved.

  The present invention solves the above-described conventional problems. For example, the present invention can be mounted on a rewritable printer and the like, prevents toner offset, and enables efficient simultaneous erasing even when a printed image is printed on both sides. An object is to provide a color device.

  In order to solve the above-described problems, the decoloring apparatus of the present invention is a printing apparatus for reusing a printing medium on which characters or images are printed using a decoloring toner containing a near-infrared absorbing dye and a decoloring agent. In the erasing apparatus of a rewritable printer for erasing the character or image printed on the medium, a transport mechanism for transporting the print medium on which the character or image is printed, and a parallel arrangement close to the transport mechanism A heat radiation heater using a near infrared ray transmitting member as a base material, and an LED light irradiation device that is disposed on the back surface of the heat radiation heater and emits decolored light that passes through the heat radiation heater, and the heat radiation heater Applies heat radiation to the print medium transported by the transport mechanism and heats it, and the LED light irradiation device applies the characters and images of the print medium heated by the heat radiation heater on the printed surface. , The above heat radiation Configured to illuminate the LED light from the rear of the heater passes through the heat radiant heater.

  In this decoloring apparatus, for example, the thermal radiation heater is disposed in parallel near and above and below the transport mechanism, and the LED light irradiation device is disposed on the back of the top and bottom transport mechanisms, respectively. You can also

  In the decoloring apparatus, the thermal radiation heater is composed of, for example, quartz glass and a transparent conductive film of ITO (indium tin oxide) applied or baked on the surface of the quartz glass.

  The erasing apparatus may further include, for example, a ceramic heater that is disposed adjacent to the heat radiation heater on the upstream side in the transport direction of the transport mechanism and preheats the print medium transported by the transport mechanism. May be. In this case, it is preferable to further comprise a heat insulating material that covers a surface other than the preheating radiation surface of the ceramic heater.

  The present invention can be mounted on, for example, a rewritable printer and the like, and has an effect that it is possible to provide a decoloring apparatus capable of preventing toner offset and efficiently performing simultaneous decoloring even when a printed image is printed on both sides.

1 is a cross-sectional view schematically showing an internal configuration of a color image forming apparatus including a decoloring apparatus according to Embodiment 1 of the present invention. FIG. 3 is a perspective view illustrating a both-side end conveyance device that sandwiches and conveys both side ends of a sheet in a sheet conveyance path of the erasing apparatus according to the first embodiment. FIG. 3 is a plan view of a sheet conveyance path of the erasing apparatus according to the first embodiment. 1 is a side view illustrating an internal configuration of a decoloring apparatus according to Embodiment 1. FIG. 6 is a side view showing an internal configuration of a decoloring apparatus according to Embodiment 2. FIG. (a) is a side view which shows the internal structure of the decoloring apparatus based on Example 3, (b) is a figure which shows the structure of the thermal radiation heater of the decoloring unit. FIG. 9 is a side view showing an internal configuration of a decoloring apparatus according to Embodiment 4. FIG. 10 is a side view illustrating an internal configuration of a decoloring apparatus according to a fifth embodiment.

  Hereinafter, embodiments of the present invention will be described in detail. Although not described in detail, the decolorizable toner described below is prepared by kneading a near-infrared absorbing dye and a decoloring agent in a resin so that the average particle size becomes 9 μm.

  However, almost no decoloring reaction is observed even when a near-infrared ray is irradiated at normal temperature on a printing medium (hereinafter also referred to as paper) printed with this decolorizable toner. When the paper is heated and the near-infrared ray is irradiated in a state where the decolorizable toner is melted, a decoloring reaction is observed.

  Therefore, the erasing apparatus needs to have two elements, an element for heating the paper and an element for irradiating near infrared rays. However, since a printer of a decolorizable toner containing this near-infrared absorbing dye is not commercially available, the contents confirmed by an experiment conducted by incorporating a prototype decoloring apparatus into a normal printer will be described below.

  According to the experiment, as a result of examining a device for heating the paper and a device for irradiating near infrared rays, the paper is heated using the radiant heat of the heater as a heat source, and the LED light is used as a near infrared light source for decoloring. It came to the conclusion that it is suitable.

  FIG. 1 is a cross-sectional view schematically illustrating an internal configuration of a color image forming apparatus including a decoloring apparatus according to Embodiment 1 of the present invention. An image forming apparatus (hereinafter simply referred to as a printer) 1 shown in FIG. 1 includes a decoloring apparatus having a heat radiation heater serving as a decoloring heat source, a light source that emits decoloring light, and a toner offset prevention mechanism.

  The printer 1 includes an endless transfer belt 3 extending in the horizontal direction at the center inside the main body housing 2. The transfer belt 3 is stretched around a drive roller 4 and a driven roller 5 while being stretched by a tension mechanism (not shown), and is driven by the drive roller 4 to circulate in a counterclockwise direction indicated by an arrow a in the figure. To do.

  Four image forming units 6 (6r (k), 6y, 6c, 6m) are arranged above the upper circulation moving surface of the transfer belt 3. The image forming unit 6r is an image forming unit for forming an erasable toner image in which the erasable toner is accommodated in the developing unit 7, and is for forming a black image (not shown) in which the black toner is accommodated in the developing unit 7. The image forming unit 6k can be exchanged with the user arbitrarily.

  The image forming unit 6y is an image forming unit for forming a yellow color in which yellow toner is accommodated in the developing unit 7, and the image forming unit 6c is for forming a cyan color image in which cyan toner is accommodated in the developing unit 7. The image forming unit 6m is an image forming unit for forming a magenta color image in which magenta toner is accommodated in the developing device 7.

  Since the four image forming units 6 have the same structure except for the type of toner contained in the developing unit 7, the image forming unit 6r will be described below and the structure thereof is simplified. explain.

  The image forming unit 6 is provided with a photosensitive drum 8 that is in contact with the upper circulating movement surface of the transfer belt 3. A developing roller held in the lower opening of the developing unit 7 is placed adjacent to the photosensitive drum 8 so as to surround the peripheral surface thereof, followed by a cleaner, an initialization charger, and an optical writing head (not shown). 9 etc. are arranged.

  The developing roller 9 carries a thin layer of black toner or decoloring toner (hereinafter, only the decoloring toner will be described) accommodated in the developing unit 7 on the surface, and a photoconductor by an optical writing head. An image of the decolorizable toner is developed on the electrostatic latent image formed on the peripheral surface of the drum 8.

  A primary transfer roller (not shown) is pressed against the lower portion of the photoconductive drum 8 via the transfer belt 3 to form a primary transfer portion there. A bias voltage is supplied to the primary transfer roller from a bias power source (not shown).

  The primary transfer roller applies a bias voltage supplied from a bias power source to the transfer belt 3 at the primary transfer portion, and an image of the decolorable toner developed on the peripheral surface of the photosensitive drum 8 is applied to the transfer belt 3. Transcript.

  The secondary transfer roller 11 is pressed against the driven roller 5 on which the right end portion of the transfer belt 3 shown in the drawing is stretched via the transfer belt 3, thereby forming a secondary transfer portion. A bias voltage is supplied to the secondary transfer roller 11 from a bias power source (not shown).

  In the secondary transfer portion, the secondary transfer roller 11 applies a bias voltage supplied from a bias power source to the transfer belt 3, and displays an image of the decolorable toner that has been primarily transferred to the transfer belt 3 from below in the figure. Are transferred to a recording medium which is conveyed as indicated by arrow b or c and further conveyed along the image forming conveyance path 12.

  The recording medium 14 conveyed as indicated by the arrow c is stacked and accommodated in the upper paper feed cassette 15, taken out by the uppermost sheet by a paper feed roller (not shown), and indicated by the arrow c. As described above, the image is conveyed to the sheet feeding conveyance path, further conveyed through the image forming conveyance path 12, and the image of the erasable toner is transferred while passing through the secondary transfer portion.

  The recording medium 14 that has passed the secondary transfer portion while the image of the decolorizable toner is transferred is conveyed along the fixing conveyance path 16 to the fixing unit 17. The heating roller 18 and the pressing roller 19 of the fixing unit 17 sandwich the recording medium 14 and convey it while applying heat and pressure.

  As a result, the image of the erasable toner that has been secondarily transferred is fixed on the paper surface of the recording medium 14, and is further conveyed by the heating roller 18 and the pressing roller 19, and is formed on the upper surface of the main body housing 2. The paper is ejected to the paper ejection tray 21 that is present.

  On the other hand, the sheet 22 conveyed as shown by the arrow b above is a sheet on which a decolorable toner image has already been formed on the sheet surface, and is taken out from the lower sheet feeding cassette 23 one by one and indicated by the arrow d. As shown in FIG.

  In this case, the paper 22 is carried into the erasing device 24. In the erasing device 24, conveyance roller / roller bodies 26 (26a, 26b) are arranged on the upstream side (left side in the figure) and the downstream side (right side in the figure) of the paper conveyance path 25, respectively.

  The two sets of transport roller / roller bodies 26 transport the paper 22 carried into the erasing device 24 from the upstream side to the downstream side along the paper transport path 25. A decoloring unit, which will be described later, is disposed in the paper transport path 25 formed between the two sets of transport rollers and roller bodies 26.

  FIG. 2 is a perspective view showing a both-side end transport device that sandwiches and transports both end portions of the sheet 22 in the sheet transport path 25 described above. In the figure, the upstream conveying roller / roller body 26a and the downstream conveying roller / roller body 26b are not shown.

  As shown in FIG. 2, an endless thin belt 31 having a pressing roller 29 at the center of the inside thereof is arranged in two upper and lower stages on both sides of the sheet conveying path 25. Both side end conveying devices 32 are arranged. As shown in the figure, the both-side end conveying device 32 holds the both-side end portions of the paper 22 in the direction of the arrow d in the figure with respect to the paper 22.

  As a result, it is possible to prevent a problem that both ends of the paper 22 are rounded due to heat or the leading end of the paper 22 hangs down and comes off from the paper transport path 25.

  FIG. 3 is a plan view of the paper transport path 25 of the erasing device 24 described above. Three heater contact prevention wires 33 (33a, 33b) shown in FIG. 3 are stretched above and below the sheet 22 conveyed in the direction of the arrow d by the conveying rollers / rollers 26a, 26b and the both-side end conveying device 32, respectively. (In the figure, the upper wire is indicated by a solid line, and the lower wire is indicated by a broken line).

  These heater contact prevention wires 33 (33a, 33b) are respectively held by wire holding portions 34 (34a, 34b). The heater contact preventing wire 33 and the wire holding portion 34 are fixedly disposed in the decoloring device 24 as a heater contact preventing device 35.

  The heater contact prevention wires 33 (33a, 33b) prevent the paper 22 from contacting a heat radiation heater, which will be described later, and suppress the roundness of the paper 22 from above and below, so that the paper 22 falls off from the both-side conveyance device 32. Is prevented.

  As described above, the decoloring device 24 shown in FIG. 1 prevents the heater 22 from being slanted from the conveying roller / roller body 26a to the conveying roller / roller body 26b while preventing the paper 22 from being rounded or drooped. To guide the paper 22.

  Since the heater contact prevention wire 33 is stretched obliquely with respect to the conveyance direction of the paper 22 and is disposed at a wide interval, the decoloring radiant heating from the heat radiant heater and the LED light source which will be described later are also provided. It can be said that there is no blocking of the erasing light from the color.

  If the erasing device 24 has a erasing structure of only one side, when the paper 22 is stored in the lower paper feed cassette 23, the image surface to be erased is set to either the upper side or the lower side. It becomes difficult to use because it must be accommodated. In this example, since both sides can be erased simultaneously, it is convenient.

  In addition, as a method of erasing both sides, a method of erasing one side, inverting the paper, and erasing the back side like a general printer having a double-sided printing mechanism can be considered. If heat necessary for erasing is once applied to a chromatic toner image and then erasing the erasable toner image on the opposite side, the erasing performance may be lowered.

  That is, the image on the back side is also heated when the first side is erased, the image on the back side is cooled during conveyance by inverting the paper 22 by the duplex printing mechanism, and the color is erased when the back side is subsequently erased. Experience has shown that performance decreases. Furthermore, since the front / back decoloring process is performed twice, there is an inconvenience that the decoloring time becomes longer.

  In this example, both sides can be erased at the same time, so there is no deterioration in the color erasing performance, good erasing performance is maintained, and the color erasing time is less than that when the front and back erasing processing is performed twice. Reduced to 2 or less.

  Even in the case of decoloring on one side, heating from both the front and back sides allows efficient heating without energy loss due to heat leakage from the back side of the paper in the case of single-sided heating. Moreover, since the set temperature of the heat radiation heater can be lowered, an effect of reducing power consumption can be expected.

  FIG. 4 is a side view showing an internal configuration of the erasing apparatus 24 shown in FIG. As shown in FIG. 4, the erasing device 24 includes a conveyance mechanism including a conveyance roller / roller body 26, a both-side conveyance device 32, and a heater contact prevention device 35 shown in FIGS. 2 and 3. A decoloring unit 38 including a ceramic heater 36 as a heat radiation heater and an LED light source 37 as a decoloring light source is provided above and below, respectively.

  The ceramic heater 36 is installed in parallel to the paper transport path 25, that is, to the paper 22. The other LED light source is arranged so that the paper 22 emits decoloring light immediately after passing through the heating part of the ceramic heater 36.

  FIG. 5 is a side view illustrating the internal configuration of the decoloring apparatus according to the second embodiment. The configuration of the printer main body is the same as that shown in FIG. 1, and the appearance of the erasing device is the same as that of the erasing device 24 shown in FIG.

  As shown in FIG. 5, the decoloring device 24 of this example includes a ceramic heater 36 as a heat radiation heater and an LED as a decoloring light source above and below a paper transport path 25 having a transport mechanism similar to that in FIG. A decoloring unit 39 including a light source 37 is provided.

  The ceramic heater 36 in the erasing unit 39 of this example is installed obliquely with respect to the paper transport path 25, that is, the paper 22 so as to be widened toward the downstream in the transport direction. The other LED light source is disposed so as to obliquely irradiate the decoloring light toward the space between the ceramic heater 36 and the paper 22.

  Here, the decoloring test result by the decoloring unit 38 of the decoloring apparatus 24 in Example 1 and the decoloring test result by the decoloring unit 39 of the decoloring apparatus 24 in Example 2 will be compared and examined. .

  Comparing the paper heating performance of the ceramic heater 36, it was found that the paper heating performance is superior to the paper 22 when the heater is installed in parallel and close to the paper 22 rather than being installed obliquely. To do. Therefore, the erasing unit 38 of the first embodiment is superior in terms of heat.

  However, when comparing the decoloring performance, the decoloring unit 39 of Example 2 that directly irradiates the decoloring light onto the paper 22 being heated has a superior decoloring capability than the decoloring unit 38 of Example 1. .

  By the way, as described above, in order to cause a decoloring reaction to an image printed with decolorable toner on the paper surface, it is necessary to heat the paper on which the image is printed. Experiments have shown that the temperature is around 200 ° C.

  In the case of the first embodiment, the LED light source 37 emits the decoloring light after the paper 22 is removed from the heating of the ceramic heater 36. In order to cause the decoloring reaction, it is necessary to keep the paper temperature in the irradiation region at about 200 ° C.

  The sheet temperature is gradually heated at the same time as it enters the heating portion of the ceramic heater 36, and reaches the maximum temperature as it passes through the heating portion. And after passing through a heating part, it is air-cooled and temperature falls sequentially.

  Therefore, after passing through the heating part of the ceramic heater 36 as described above, the temperature of the paper is maintained at about 200 ° C. over a long range until the irradiation of the decoloring light from the LED light source 37 is completed. It is considered that the paper temperature just below the heating unit has reached over several tens of degrees Celsius.

  In such a temperature environment, it is easily considered that a part of the decolorizer may be thermally destroyed. Also, since the air temperature is constantly changing, it is difficult to stabilize the paper temperature after the start of air cooling.

  In particular, when the ambient temperature is low and the air is cold, the ceramic heater 36 needs to be set to a higher temperature. As a result, the temperature of the paper becomes higher and the decoloring agent for the decolorable toner becomes disadvantageous.

  On the other hand, in the case of Example 2, the decoloring light from the LED light source 37 is obliquely irradiated so that the decoloring light enters directly below the ceramic heater 36. Since the maximum temperature of the paper 22 is around the heater heating section, the irradiation region of the LED decoloring light is below this temperature.

  For this reason, the thermal destruction of the color erasing agent of the color erasable toner is suppressed to a minimum as compared with the case of the first embodiment. It can be considered that the thermal destruction of the color erasing agent can be suppressed to a minimum because Example 2 has a problem in heating efficiency as compared with Example 1 but has excellent color erasing performance.

  Therefore, the inventor considered how to realize a decoloring unit having good heating efficiency and excellent decoloring performance. In order to improve the heating efficiency, it was considered to arrange the heater in parallel with the paper being conveyed, and in order to improve the color erasing performance, the paper being heated was irradiated with decoloring light.

  The above idea is realized by heating the paper from the back side and irradiating the surface with the decoloring light. However, it can only decolor one side of the paper. Therefore, the inventor's idea has reached to construct the heat radiation heater of the decoloring unit with a material through which the decoloring light is transmitted.

  FIG. 6A is a side view showing the internal configuration of the erasing apparatus according to the third embodiment, and FIG. 6B is a diagram showing the configuration of the heat radiation heater of the erasing unit. The configuration of the printer main body is the same as that shown in FIG. 1, and the appearance of the erasing device is the same as that of the erasing device 24 shown in FIG.

  The heat radiation heater of this example is composed of a glass heater 40. The glass heater 40 uses a quartz glass plate 41 as a substrate, and a transparent conductive film 42 made of an ITO (indium tin oxide) film is applied or baked on one surface of the quartz glass plate 41. A silver paste electrode 43 is provided.

  When the electrode is energized, Joule heat is generated by the transparent conductive film 42 and is heated together with the quartz glass, and far infrared rays are radiated from the glass surface. The glass heater 40 is currently commercially available from Blast Corporation.

  According to Blast Co., Ltd., the heating capacity of the glass heater 40 is a maximum of 500 ° C., and the power consumption is a maximum of 5 W / cm = ^ 2, which is a low power consumption. Further, the temperature rises quickly and is 100 ° C./5 seconds, which sufficiently maintains the performance that can be used as a heater.

  Further, the light transmittance is 85%, and the LED light is considerably transmitted. This glass heater 40 is a highly reliable product that has been used for over 4 years since being put on the market.

  As shown in FIG. 6A, the glass heater 40 is disposed in parallel and close to the paper transport path 25 (paper 22) of the erasing device 24. And the LED light source 37 is arrange | positioned so that a decoloring light may be irradiated from a perpendicular direction with respect to the back surface of a heater.

  When the erasing unit 44 comprising the glass heater 40 and the LED light source 37 is used, the paper 22 carried into the erasing device 24 is heated while passing directly under the glass heater 40 and is heated in the latter half of the heater heating unit. The paper 22 is irradiated with decoloring light from the LED light source 37 that transmits through the glass heater 40 with a transmittance of 85%.

  As a more specific operation, first, the glass heater 40 is powered on. When the radiation temperature of the glass heater 40 reaches 350 ° C., the paper 22 printed with the erasable toner is fed to the erasing device 24 from the left side of the drawing by the conveying roller / roller body 26a.

  At this time, the linear speed of conveyance is 15 mm / second. The paper 22 is heated by the glass heater 40 as it is conveyed. When the paper 22 reaches the irradiation area of the LED light source 37, the paper 22 is heated to about 200 ° C.

  Here, the decoloring light from the LED light source 37 is irradiated perpendicularly to the back surface of the glass heater 40. The irradiated decoloring light passes through the glass heater 40 and is irradiated onto the paper 22, and the decolorizable toner image on the irradiated surface is decolored.

  The paper 22 from which the color erasable toner image has been erased is discharged from the color erasing device 24 by the conveyance roller / roller body 26b on the right side of the drawing and conveyed to the next step.

  As described above, the parallel arrangement of the thermally radiant heater of Example 1 which is excellent in heat with respect to both sides of the paper 22 and the simultaneous irradiation of the erasing light having excellent erasing performance of Example 2 are provided. This is realized by the decoloring unit 44 of the third embodiment.

  In the configuration of the second embodiment, in order to irradiate the decoloring light to the sheet 22 being heated, the sheet 22 must be irradiated in an oblique direction. In this case, the irradiation surface of the decoloring light to the sheet 22 advances on the sheet. It becomes a plane extending in the direction (an ellipse when the LED light is circular radiation), and its illuminance distribution is complicated.

  In the case of oblique irradiation, even if the irradiation angle is slightly changed, the flatness of the irradiated surface (eccentricity in the case of an ellipse) changes greatly, and the irradiation position also moves. Therefore, in order to set the optimum condition, confirmation must be advanced while accurately measuring the exact LED position and inclination. In mass production, strict positional accuracy is required.

  The irradiation surface from the vertical direction as in Example 3 is circular except when a special lens is used, and the irradiation distribution is simple and easy to understand. The irradiation point is easy to position. Therefore, there is an advantage that the setting of optimum conditions and mass production become much easier.

  FIG. 7 is a side view illustrating the internal configuration of the decoloring apparatus according to the fourth embodiment. The configuration of the printer main body is the same as that shown in FIG. 1, and the appearance of the erasing device is the same as that of the erasing device 24 shown in FIG.

  Further, in FIG. 7, only parts necessary for explanation are given numbers. Other configurations are the same as those in the case of FIG. As shown in FIG. 7, the ceramic heater 36 and the glass heater 40 are arranged adjacent to each other in the heat radiation heater of the decoloring unit 45 of this example.

  In this configuration, the glass heater 40 in FIG. 6 is replaced with a ceramic heater 36 on the upstream side in the transport direction where there is no need to transmit the decoloring light. And it is comprised so that the temperature setting of the ceramic heater 36 and the glass heater 40 can be set independently, respectively.

  The ceramic heater 36 has a function of heating the paper 22 until the temperature reaches 200 ° C. The glass heater 40 has a function of radiating the minimum amount of heat necessary to maintain the temperature of 200 ° C. to maintain the temperature of the paper 22 at 200 ° C. Since the cost of the glass heater is high, the cost can be reduced by replacing the upstream side with a ceramic heater.

  In addition, this method can reduce the power slightly. In addition, when the paper 22 is heated, the water contained in the paper 22 is vaporized, and a part of the paper component contained in the vaporized water may contaminate the periphery of the heater.

  This vaporized component is mainly generated in the first half of heating from room temperature to about 200 ° C. The first half is reliably heated to 200 ° C. by the ceramic heater 36. This causes the vaporized component to be discharged in the area where the ceramic heater 36 is disposed. Thereby, contamination of the glass heater 40 of the latter half can be suppressed more.

  By the way, the heat radiation heater radiates heat from the surface opposite to the sheet 22 and also from the opposite surface, so that it is cooled by air and heat is taken away. Therefore, power consumption can be reduced if this air cooling can be suppressed as much as possible.

  FIG. 8 is a side view illustrating the internal configuration of the decoloring apparatus according to the fourth embodiment. The configuration of the printer main body is the same as that shown in FIG. 1, and the appearance of the erasing device is the same as that of the erasing device 24 shown in FIG. Further, in FIG. 8, only parts necessary for explanation are given numbers. Other configurations are the same as those in the case of FIG.

  As shown in FIG. 8, the ceramic heater 36 and the glass heater 40 are also arranged adjacent to each other in the heat radiation heater of the decoloring unit 46 of this example. And in the decoloring unit 46 of this example, the heat insulating material 47 which covers surfaces other than the thermal radiation surface of the ceramic heater 36 is arrange | positioned.

  Thus, by covering the ceramic heater 36 with the heat insulating material, heat conduction, radiant heat, and air cooling can be suppressed to some extent. According to the experiment, when the back surface of the ceramic heater 36 was covered with glass wool having a thickness of 10 mm to insulate, the electric power could be reduced by 10% to 20% when the heater temperature was set to 450 ° C.

  The installation of the heat insulating material 47 can also be carried out in FIG. 6A, and the power can be reduced by covering the outside of the range irradiated with the decoloring light with the heat insulating material 47.

  The present invention can be used for an erasing apparatus mounted on, for example, a rewritable printer.

1. Image forming device with erasing function (printer)
DESCRIPTION OF SYMBOLS 2 Main body apparatus housing | casing 3 Transfer belt 4 Drive roller 5 Driven roller 6 (6r (6k), 6y, 6c, 6m) Image formation unit 7 Developer 8 Photoconductor drum 9 Development roller 11 Secondary transfer roller 12 Image formation conveyance path DESCRIPTION OF SYMBOLS 14 Recording medium 15 Upper sheet cassette 16 Fixing conveyance path 17 Fixing part 18 Heating roller 19 Pressing roller 21 Paper discharge tray 22 Recording medium (paper)
Reference Signs List 23 Lower sheet cassette 24 Decoloring device 25 Recording medium (paper) transport path 26 (26a, 26b) Transport roller / roller body 27 Drive roller 28 Driven roller 29 Pressing roller 31 Thin belt 32 Both end transport device 33 (33a, 33b) ) Heater contact prevention wire 34 (34a, 34b) Wire holder 35 Heater contact prevention device 36 Ceramic heater 37 LED light source 38, 39 Decoloring unit 40 Glass heater 41 Quartz glass plate 42 Transparent conductive film (ITO (indium tin oxide) film) )
43 Electrode 44, 45, 46 Decoloring unit 47 Thermal insulation

Claims (5)

A rewritable printer for erasing the characters and images printed on the printing medium in order to reuse the printing medium on which the characters and images are printed by using a decolorizable toner containing a near-infrared absorbing dye and a decoloring agent. In the erasing device,
A transport mechanism for transporting the print medium on which the characters and images are printed;
A thermal radiation heater that is arranged in parallel in the vicinity of the transport mechanism and has a near-infrared transmitting member as a base material;
An LED light irradiation device that is disposed on the back surface of the thermal radiation heater and emits decolored light that passes through the thermal radiation heater;
Have
The heat radiation heater applies heat radiation to the print medium transported by the transport mechanism and heats it,
The LED light irradiating device irradiates LED light through the thermal radiation heater from the back side of the thermal radiation heater onto a printing surface on which the characters and images of the printing medium heated by the thermal radiation heater are printed. To
A decoloring device characterized by that.   2. The heat radiation heater is disposed in parallel near and above and below the transport mechanism, and the LED light irradiation devices are disposed on the back surfaces of the top and bottom transport mechanisms, respectively. Erasing device.   3. The decoloring according to claim 1, wherein the thermal radiation heater comprises quartz glass and a transparent conductive film of ITO (indium tin oxide) applied or baked on the surface of the quartz glass. apparatus.   The ceramic heater which is arrange | positioned adjacent to the said thermal radiation heater in the conveyance direction upstream of the said conveyance mechanism, and pre-heats the said printing medium conveyed by the said conveyance mechanism is further provided. Erasing device.   The decoloring apparatus according to claim 4, further comprising a heat insulating material covering a surface other than the preheating radiation surface of the ceramic heater.