JP2012123026A - Decoloring apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a decoloring apparatus which is effective for reducing power consumption by minimizing the thermal loss due to convection, radiation, and thermal conduction.SOLUTION: A decolorization part 40 of a decoloring apparatus comprises: conveyance roller rotating bodies 4a, 4b disposed upstream and downstream of a paper conveyance path 3, respectively, and heat radiation heater parts 31 (31a, 31b) and decolorization light sources 8 (8a, 8b) disposed above and below the paper conveyance path 3, respectively. Upon radiation of radiant heat from the heat radiation heater parts 31 to a sheet on which a color-erasable toner image is formed conveyed in the direction of an arrow a, decolorization light is irradiated from the decolorization light sources 8. The heat radiation heater parts 31 (31a, 31b) has: first heat insulation parts 33 which thermally seal portions other than heat radiation surfaces 32 (32a, 32b) from the outside, and second heat insulation parts 35 which surround the peripheries of decolorization areas 34 (34a, 34b) except the peripheries where the decolorization light of the decolorization light sources 8 passes. The peripheries where the decolorization light passes comprises quartz glass plates 37 (37a, 37b) excellent in light permeability and thermal resistance, and are thermally sealed from the outside.

Description

  The present invention relates to a color erasing apparatus, and more particularly, to a color erasing apparatus effective in reducing power consumption, that is, reducing power consumption by minimizing heat loss due to convection, radiation, and heat conduction.

  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 and excites, 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

  By the way, normally, a decoloring device is considered to be a heating device that heats the printing surface of a sheet on which an image of the decolorable toner is printed, and a near-infrared light that irradiates the printing surface of the heated sheet. An infrared light generator.

  As such a structure, there are two devices that share both an infrared light emitting device and a heating device such as an LED lamp and a heater device, and a device that includes both an infrared generator and a heating device such as a halogen lamp. It is thought that it consists of.

  However, halogen lamps have the disadvantages of high power consumption and short life. In addition, the combination of the two devices, the LED lamp and the heating device, has a big problem regarding power consumption such as heat loss due to convection, radiation, and heat conduction of the heating device.

  However, in the decoloring device combining both the infrared ray generator and the heating device in Patent Document 1, no consideration is given to the problem of heat loss due to convection, radiation, and heat conduction of the heating device. Therefore, there is no disclosure or suggestion about problems such as reduction of power consumption related to such heat loss.

  The present invention solves the above-described conventional problems, and provides a decoloring apparatus effective in reducing power consumption, that is, reducing power consumption by minimizing heat loss due to convection, radiation, and heat conduction. Objective.

  In order to solve the above-described problems, the erasing apparatus according to the present invention provides the erasing of the paper disposed above and below the paper transport path so as to erase the erasable toner images printed on both sides of the paper. A thermal radiation heater that heats the printing surface of the color toner image and an eraser on the printing surface of the decoloring toner image of the paper that are respectively disposed above and below the paper conveyance path and heated by the thermal radiation heater. A decoloring light source that emits colored light, a first heat insulating part that thermally seals a portion other than the heat radiation surface of the heat radiation heater from the outside, heat radiation of the heat radiation heater, and decoloring light of the decolorization light source A second heat-insulating portion surrounding the periphery of the decoloring region that receives the irradiation of the decoloring light source except the periphery through which the irradiation light of the decoloring light passes, and the decoloring light of the decoloring light source The second heat insulation provided at the periphery through which the irradiation light passes, In cooperation with the configured and a heat translucent glass plate for shielding thermally externally the decoloring area.

  In this decoloring apparatus, the decoloring light source is configured to be composed of, for example, an LED (light emitting diode) that emits near infrared light. Moreover, you may comprise the said heat-resistant translucent glass plate so that it may consist of quartz glass, for example.

  Moreover, it is preferable that the first heat insulating portion is made of, for example, an inorganic fiber heat insulating material and is formed so as to surround the outer surface of the heat source other than the heat radiating surface. Moreover, it is preferable that the said 2nd heat insulation part consists of a plate-shaped member of an inorganic fiber type heat insulating material, for example.

  The present invention has an effect that it is possible to provide a decoloring apparatus effective for reducing power consumption, that is, reducing power consumption by minimizing heat loss due to convection, radiation, and heat conduction.

It is sectional drawing which shows the basic composition of the decoloring apparatus which concerns on Example 1 of this 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 exemplary embodiment. FIG. 3 is a plan view of a sheet conveyance path of the erasing apparatus according to the first embodiment. (a) is an enlarged view showing the basic configuration of the erasing unit arranged above and below the paper transport path of the erasing unit of the erasing apparatus according to the first embodiment, and (b) is a temperature measurement method during the experiment. FIG. It is a graph which shows one example of electric power value transition when the electric power of only a heater is measured immediately after electricity supply of the decoloring unit of the decoloring part of the decoloring apparatus according to Example 1 together with the temperature of the heater. It is the graph which calculated | required and showed the electric power of the stable state from the measurement in control temperature 350 degreeC, 400 degreeC, and 450 degreeC. 6 is a graph showing the power of only the heater in the stable state of the decolored portion in the improved type of Example 1 from the measurements at control temperatures of 350 ° C., 400 ° C., and 450 ° C., together with the case before improvement for reference. FIG. 5 is a diagram showing three temperature measurement fixed points of a metal frame (main body casing) in the improved type of the first embodiment. (a) is a graph showing the transition of the measured temperature at three temperature measurement fixed points during 400 ° C. control in a metal frame with an aperture ratio of 10% in the improved type of Example 1, and (b) is the metal before improvement for reference. It is a graph which shows transition of the same measurement temperature in a flame | frame. 6 is a cross-sectional view illustrating a configuration of a decoloring unit of a decoloring apparatus according to Embodiment 2. FIG. (a) is the graph which shows transition of the temperature of each part of a metal frame in the decoloring part of the decoloring apparatus which concerns on Example 2 at the control temperature of 400 degreeC, (b) is when only energizing only a heater at the control temperature of 400 degreeC It is a graph which shows the heater electric power value at the time of the stability of the erasing part of Example 2 with the electric power value of the erasing part of Example 1 for reference. 6 is a cross-sectional view illustrating a configuration of a decoloring unit of a decoloring apparatus according to Embodiment 3. FIG. (a) is the graph which shows transition of the temperature of each part of three temperature measurement fixed points of the metal frame in the decoloring part of the decoloring apparatus which concerns on Example 3 in the control temperature of 400 degreeC, (b) is the heater of the same decoloring part The power in the stable state when the control temperature is 350 ° C., 400 ° C., and 450 ° C. during the operation of only the head portion and during the operation of executing the decoloring process is the stable state when the heater portion of the first and second embodiments is in operation. It is a graph shown with the electric power of.

  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 sheet is heated and near-infrared rays are irradiated in a state where the decolorizable toner is melted, a decoloring reaction is first 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, a printer or the like that forms an image on a sheet with a decolorizable toner containing the near-infrared absorbing dye is not commercially available.

  Therefore, in the following embodiments, a monochrome image forming unit of a normal printer is filled with a decolorable toner, and an image of the decolorable toner is printed on a normal sheet (hereinafter also referred to as “printing”). The content confirmed by the experiment conducted using the paper on which the toner image is printed will be described.

  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 LED light is used as a near-infrared light source for decoloring. I came to the conclusion that this is appropriate.

  FIG. 1 is a cross-sectional view illustrating a basic configuration of the decoloring apparatus according to the first embodiment. This erasing device is a erasing device that was prototyped to investigate the performance of the heat source of the erasing unit incorporated in the erasing device. This configuration is the basic configuration, and the heat source of the erasing device with this basic configuration The following is a description of the experimental results obtained by sequentially changing other configurations.

  First, in the erasing apparatus 1 having the basic configuration according to the first embodiment shown in FIG. 1, a sheet conveyance path 3 for conveying a sheet to be decolored in the erasing unit is disposed inside the main body housing 2. Yes. Conveying roller / roller bodies 4 (4a, 4b) are arranged on the upstream side (left side in the figure) and the downstream side (right side in the figure) of the sheet conveying path 3, respectively.

  A paper feed cassette 5 and a paper storage cassette 6 are arranged upstream and downstream of the paper transport path 3, that is, upstream of the transport roller / roller body 4a and downstream of the transport roller / roller body 4b. It is installed.

  Although not shown in the drawing, the sheet feeding cassette 5 has at least one image formed with an erasable toner on a bottom plate 11 that is urged from below by a push-up spring (not shown). A sheet of paper is placed.

  Further, the erasing apparatus 1 includes erasing units 9 (9a, 9b) each including a thermal radiation heater unit 7 (7a, 7b) and a erasing light source 8 (8a, 8b) above and below the paper conveyance path 3, respectively. ing. A decoloring section 10 is constituted by the sheet conveyance path 3, the heat radiation heater section 7 and the decoloring light source 8.

  As indicated by an arrow “a” from the paper feed cassette 5, the sheets taken out one by one by a paper feed roller (not shown) and fed to the transport roller / roller body 4 a of the erasing unit 10 are transferred to the transport roller / roller body. The paper is fed to the paper transport path 3 by 4a.

  The paper fed to the paper transport path 3 is transported from the upstream side to the downstream side along the paper transport path 3 by a both-side end transport device described later in detail. Radiant heat is radiated from the heat radiation heater section 7 to the image forming surface of the conveyed paper by the decolorizable toner.

  The decolorable toner image forming surface of the paper heated by the radiation heat radiation from the heat radiation heater unit 7 is irradiated with the decoloring light from the decoloring light source 8, and the decolorable toner image on the paper is erased. The The paper on which the color erasable toner image has been erased is taken over by the transport roller / roller body 4b and discharged to the paper storage cassette 6 as indicated by an arrow b.

  The paper storage cassette 6 also includes a bottom plate 12 that is pressed and urged from below by a push-up spring (not shown). The paper discharged to the paper storage cassette 6 is pressed from above by a pressing claw (not shown) against the urging force of the push-up spring and placed on the bottom plate 12.

  The paper on which the color erasable toner image stored in the paper storage cassette 6 has been erased is taken out one by one by a paper supply roller (not shown) as required, and a paper supply path 14 by a pair of conveyance rollers 13. And is sent out of the machine as indicated by an arrow c.

  The paper sent out of the machine is regenerated as a printed material after a new image is formed on the paper by an image forming apparatus such as a printer, a copying machine, or a facsimile machine installed outside the machine.

  FIG. 2 is a perspective view showing a both-side end conveying device that nipped and conveys both end portions of the sheet in the sheet conveying path 3 described above. In the drawing, the illustration of the conveyance roller / roller body 4a on the upstream side in the sheet conveyance direction and the conveyance roller / roller body 4b on the downstream side is omitted.

  As shown in FIG. 2, on both sides of the sheet conveying path 3, an endless thin belt 18 having a pressing roller 17 at the center of the inside thereof is arranged in two upper and lower stages. Both side end conveying devices 19 are arranged.

  The both-side end conveying device 19 sandwiches both end portions of the paper 20 and conveys it in the direction of arrow a in FIG. As a result, it is possible to prevent such a problem that both ends of the sheet 20 are rounded by heat, or the leading end of the sheet 20 hangs down and comes off from the sheet transport path 3.

  FIG. 3 is a plan view of the sheet conveyance path 3 of the erasing apparatus 1 described above. Three heater contact prevention wires 21 (21a, 21b) shown in FIG. 3 are stretched above and below the sheet 20 conveyed in the direction of arrow a by the conveying rollers / rollers 4a, 4b and the both-side end conveying device 19, 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 21 (21a, 21b) are respectively held by wire holding portions 22 (22a, 22b). The heater contact preventing wire 21 and the wire holding portion 22 are fixedly disposed in the decoloring apparatus 1 as a heater contact preventing device 23.

  This heater contact prevention wire 21 (21a, 21b) prevents the paper 20 from coming into contact with the heat radiation heater section 7, and suppresses the roundness of the paper 20 from above and below, so that the paper 20 falls off the both-side end conveying device 19. Is prevented.

  As described above, the decoloring apparatus 1 shown in FIG. 1 has the heater contact prevention wire 21 that is stretched obliquely from the conveying roller / roller body 4a to the conveying roller / roller body 4b while preventing the paper 20 from being rounded or drooping. To guide the paper 20.

  Since the heater contact preventing wire 21 is stretched obliquely with respect to the conveyance direction of the paper 20 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 apparatus 1 has a erasing structure with only one side, when the paper 20 is stored in the paper feeding cassette 5, the image surface to be erased is set to either the upper side or the lower side. It becomes inconvenient 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 20 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. 4A is an enlarged view showing the basic configuration shown in FIG. 1 of the erasing unit of the present example arranged above and below the sheet conveying path 3 constituted by the sheet conveying mechanism of the erasing unit 10. FIG. 5B is a diagram specifically showing a temperature measurement method during the experiment.

  4A and 4B, the same components as those shown in FIG. 3 are denoted by the same reference numerals as those in FIG. Further, in FIGS. 4A and 4B, the paper both-side end conveyance device 19 is not shown. For the heater contact prevention mechanism 23, only the heater contact prevention wire 21 is shown.

  The erasing unit 9 (9a, 9b) of the erasing unit 10 shown in FIG. 4 (a) has a sheet conveyance path 3 and a heat radiation heater section 7 (up and down arranged with the sheet conveyance path 3 as planes of symmetry). 7a, 7b) and the decoloring light source 8 (8a, 8b) are described above.

  As shown in FIG. 4 (a), the heat radiation heater section 7 is composed of a heater 28 and a heater holding metal member 29. The decoloring light source 8 includes a light source unit frame 25, and an LED 26 and a lens 27 held at the back and front of the light source unit frame 25, respectively.

  Originally, the light source of the decoloring light source is not particularly limited as long as it is a light source that emits light in the absorption wavelength range of the infrared thermosensitive dye, but preferably it can irradiate mainly light around 820 nm which is the first absorption band. Efficient decoloring light.

  As the light source of this example, an LED 26 is used as a power-saving light source. As the LED 26, an Alwan Electronics (OP6-8510HP2) LED that emits light having a wavelength distribution with a center wavelength of 850 nm and a half width of 50 nm or more is used.

  Fifteen LEDs 26 are arranged in a direction orthogonal to the paper passing direction, and a lens 27 having a focal length of 30 mm is arranged in front of these LEDs 26 to constitute the decoloring light source 8. The lens 27 is a SELFOC lens (Japanese plate glass trademark).

  The decoloring light source 8 is installed so that the paper 20 passing between the upper and lower heat radiation heaters 7 can be irradiated with a width of about 40 mm from a distance of about 150 mm. Then, in order to efficiently irradiate the paper surface being heated by the thermal radiation heater unit 7 with the decoloring light, the decoloring light is irradiated to the paper from an oblique position with an angle of about 30 degrees with respect to the paper transport path 3. At this time, the sheet conveyance speed is 15 mm / sec.

  As shown in FIG. 4B, in the heat radiation heater section 7 described above, the heat radiation surface (paper heating surface) 31 of the heater 28 is formed substantially flat. The sheet 20 conveyed to the erasing unit 10 is heated by receiving heat radiation from the heat radiation surface 31 of the heater 28 of the heat radiation heater unit 7.

  Simultaneously with this heating, near-infrared light is irradiated from an oblique direction by the LED 26 of the decoloring light source 8. As a result, the color erasable toner image formed on the surface of the paper 20 is efficiently erased.

  By the way, the near-infrared absorbing dye contained in the decolorable toner is blended to absorb and excite near-infrared light and react with the decoloring agent to make it colorless, but the dye in the toner binder resin is Even when absorbing near infrared rays, almost no decoloring reaction is observed at room temperature. For this reason, it is effective to irradiate near infrared rays after heating, preferably simultaneously with heating, as described above.

  Among the constituent members of the erasing apparatus 1, the heater 28 is a member that enters the most power consuming member. Therefore, it is an important requirement to efficiently heat the sheet 20 while suppressing the power used by the heater 28 as much as possible.

  Although not shown, the metal frame is the base of the erasing apparatus 1 so that an opening corresponding to an opening ratio of about 40% to 50% can be formed so that heat is not generated inside and the temperature is not increased. This structure is designed to ensure an air flow path.

  Here, components and measuring instruments related to the heater 28 will be described. The heater 28 is an Infrastein B heater (NGK ceramic heater), rated = 100V, 200W. Further, in the heat radiation heater section 7 shown in FIG. 4A, three heaters 28 are arranged on the heater holding metal member 29. When the upper and lower heat radiation heaters 7 are combined, a total of six are provided.

  For the measuring device, a K thermocouple 32 (FIG. 4B shows the connection of the K thermocouple 32 to the heater 28) was used as the temperature sensor. GR3000 (manufactured by Keyence Corporation) was used as a recorder. This data capture speed is 0.01 seconds. The power meter was a power high tester 3332 (manufactured by Hioki Electric Co., Ltd.), the temperature controller was MTCD (manufactured by MISUMI Corporation), and PID control was used as the temperature control method.

  PID control is proportional operation (P operation) that produces an output proportional to the deviation between the current value and the set value, integration operation (I operation) that produces an output proportional to the integral of the deviation, and proportional to the differential of the deviation. This is a control method for outputting the sum of the differential action (D action) for outputting and controlling toward the target value.

  Hereinafter, a result is demonstrated based on the electric power value at the time of supplying with electricity to the decoloring part 10 of the decoloring apparatus 1 of this example. In the following description, the terms “power value in a stable state” or “power in a stable state” are frequently used, and what state is indicated by the stable state or the stable time will be described.

  FIG. 5 is a graph showing an example of power value transition immediately after energization. The power value is measured only for the heater, and does not include power consumption for control and driving. In addition, the graph of FIG.

  Further, since the power value is subjected to PID control, it is frequently turned on / off. Therefore, the average power is obtained by the equation “average power value = ΣW * Δt / ΣΔt” (where ΣΔt = 5 minutes, Δt = 0.01 seconds) and graphed.

  As can be seen from this graph, the power value hardly changes after the operation time of 600 seconds. In other words, it is considered that it has entered a stable state. In this stable state portion, the average value immediately before the end of the measurement in this experiment is adopted.

  FIG. 6 is a graph showing power in a stable state obtained from measurements at control temperatures of 350 ° C., 400 ° C., and 450 ° C. Moreover, although the two lines of a solid line and a broken line are described in the graph of the figure, these display the following data.

  That is, the solid line is a power value measured in a state where only the heater is energized without passing the paper. On the other hand, the broken line is a power value measured by actually operating the decoloring action through the paper. Note that the sheet conveyance linear velocity is 15 mm / sec.

  Currently, the heater temperature setting at the time of erasing is 400 ° C. Therefore, considering that, the power for energizing only the heater without passing through the paper requires 719 W, and the power for the erasing operation requires 764 W. I understand that.

  The erasing apparatus 1 of this example is intended for use in a general office, and can be integrated with a printer capable of printing with erasable toner. Considering the current situation where various devices such as personal computers and electrical facilities are used in the office, it is necessary to reduce the power consumption of the printer and the color erasing apparatus to 1500 W or less.

  Since about 1 KW is required for the decoloring operation, it can be easily predicted that the power consumed by the whole including the printer exceeds 1.5 KW. Therefore, power reduction is necessary.

  Next, an improved configuration that can further reduce the power consumption of the erasing unit 10 having the basic configuration shown in FIG. 4 will be described. By the way, as described above, the metal frame which is the base of the decoloring apparatus 1 is designed so that an opening corresponding to an opening ratio of 40% to 50% can be formed.

  Therefore, the inventor firstly considered that heat loss due to air convection can be suppressed considerably by lowering the aperture ratio of the metal frame, and thus the power can be reduced. The design was changed to a percentage.

  FIG. 7 is a graph showing power consumption in a stable state of the heater 28 obtained from measurements at control temperatures of 350 ° C., 400 ° C., and 450 ° C. when a metal frame having an aperture ratio of 10% is used. Moreover, the graph of the same figure also shows the measurement results when using a metal frame with an aperture ratio of 40% to 50 before improvement for reference.

  That is, in the graph shown in FIG. 7, the alternate long and short dash line graph indicates the power consumption of the heater when the metal frame has an aperture ratio of 10%, and the broken line graph indicates the metal frame when the aperture ratio is 40% to 50%. It is a graph which shows the power consumption of a heater.

  FIG. 7 shows that the heater power consumption when the metal frame has an aperture ratio of 10% is reduced by about 75 to 100 W compared to the heater power consumption when the metal frame has an aperture ratio of 40% to 50%. I understand. Here, the inventor decided to see the transition of the temperature of each part of the metal frame at the time of 400 ° C. control.

  FIG. 8 is a view showing three temperature measurement fixed points of the metal frame (main body housing 2 shown in FIG. 1). Point d is the center of the top plate of the metal frame 2, point e is above the side frame of the metal frame 2, and point f is the center of the side frame of the metal frame 2.

  FIG. 9 (a) is a graph showing the transition of the measured temperature at three temperature measurement fixed points during 400 ° C. control in a metal frame with an aperture ratio of 10%, and FIG. It is a graph which shows transition of the same measurement temperature in a 50% metal frame.

  When the above graphs are combined, as shown in FIG. 7, the aperture ratio is 10% compared to the heater power consumption 719 W when the metal frame has an aperture ratio of 40% to 50% with respect to the temperature control of 400 ° C. In the metal frame, the heater power consumption decreased by about 80 W to 638.3 W.

  However, as can be seen by comparing the heater power consumption shown in the graphs of FIGS. 9 (a) and 9 (b), it is compared with the measured temperatures at the three temperature measurement fixed points when the metal frame has an aperture ratio of 40% to 50%. In the metal frame having an aperture ratio of 10%, heat is filled inside, and the temperature of the metal frame main body rises by about 20 ° C. to 30 ° C., which causes a new problem.

  Therefore, the inventor considered that the heat was wasted except for the heat acting on the area where the color was actually erased in the paper transport path 3 of the color erasing apparatus 1. In order to reduce this wasted heat, the following was performed. This will be described below as a second embodiment.

  FIG. 10 is a cross-sectional view illustrating a configuration of a decoloring unit of the decoloring apparatus according to the second embodiment. The overall configuration of the decoloring apparatus is the same as the basic configuration of FIG. 1 except for the configuration of the heat radiation heater unit 7 of the decoloring unit 10. In FIG. 10, the same components as those in FIG. 4 (a) are indicated by the same reference numerals as those in FIG. 4 (a).

  As shown in FIG. 10, the decoloring part 30 of the decoloring apparatus of this example has a large change in the heat radiation heater part. That is, the heat radiation heater 31 (31a, 31b) of the decoloring section 30 of the present example first has the heat radiation surface 32 (32a, 31b) of the heat radiation heater 7 (7a, 7b) shown in FIG. A first heat insulating portion 33 is provided to thermally seal portions other than 32b) from the outside.

  The first heat insulating portion 33 is made of, for example, an inorganic fiber heat insulating material. Specifically, for example, iso wool (Iso Wool Industry Co., Ltd.) is used. Isowool has a heat resistant temperature of 1260 ° C. and a thermal conductivity of 0.08 W / m · K. Depending on the position of use, bulk isowool and 6 mm thick sheet type isowool are used separately.

  As a result, the first heat insulating portion 33 is formed by surrounding the outer surface of the portion other than the heat radiating surface (heat radiating surface 32) of the heat radiating heater portion 7 with iso wool so as to be solidified.

  The first heat insulating portion 33 is configured to radiate heat from the surface of the heater 28 other than the paper facing surface (heat radiation surface 32) of the heater 28 and heat the air to warm and convection, thereby causing heat loss. In order to prevent the generation of heat, the heat radiation and air convection are minimized by covering with a heat insulating material so that portions other than the heat radiation surface 32 of the heater 28 are not exposed to the outside.

  By the way, the heater holding metal 29 is a metal, that is, a good heat conductor, and becomes high temperature because it directly holds the heater 28. Therefore, air convection also occurs from the heater holding bracket 29. Accordingly, the heater holding metal fitting 29 also covers the surface with the first heat insulating material 33.

  Further, the thermal radiation heater unit 31 emits the erasing light of the decoloring light source 8 in the periphery of the decoloring region 34 (34a, 34b) that receives the thermal radiation of the heater 28 and the erasing light of the decoloring light source 8. The 2nd heat insulation part 35 surrounding the circumference | surroundings except the circumference | surroundings which pass is provided. In addition, since it is sectional drawing in FIG. 10, the 2nd heat insulation part 35 in the paper surface depth direction near side cannot be seen.

  This 2nd heat insulation part 35 consists of the plate-shaped member which made the inorganic fiber type heat insulating material into the plate shape, for example. Specifically, for example, HIPHA (Misumi Co., Ltd.) is used. As HIPHA, one having a heat resistant temperature of 500 ° C., a thermal conductivity of 1.21 W / m · K, and a plate thickness = 3 mm is used.

  The second heat insulating portion 35 is configured to shield the decoloring region 34 from the outside as much as possible to minimize the convection of the air in order to prevent the air in the decoloring region 34 from being heated and convection and causing heat loss. The purpose is to suppress it.

  Further, heat loss due to heat conduction also occurs at the connecting portion between the heater holding metal 29 and a main body frame (not shown). In order to prevent this heat conduction, a heat insulating support member 36 made of a heat insulating board is interposed between the heater holding metal fitting 29 and the main body frame, and the heater holding metal fitting 29 is fixed to the main body frame.

  FIG. 11 (a) is a graph showing the transition of the temperature of each part of the metal frame at a control temperature of 400 ° C. in the decoloring section 30 having the above configuration, and FIG. It is a graph which shows the heater electric power value at the time of the stability of the decoloring part 30 when it was performed with the electric power value of the decoloring part 10 for reference.

  In the decoloring part 30, as can be seen from FIG. 11 (a), the temperatures at the three temperature measurement fixed points are all within a relatively low temperature range of approximately 36 ° C. to 42 ° C. The temperature of the side frame can be suppressed to substantially the same level as the temperature of the side frame when the aperture ratio is 40% to 50%.

  Moreover, in the decoloring part 30, the heater electric power value is 611W so that FIG.11 (b) may show. This is because the power is reduced by about 100 W or more as compared with the case where the aperture ratio of the decoloring portion 10 is 40% to 50%.

  By the way, in the configuration of the decoloring unit 30 described above, considering the degree of shielding from the outside of the decoloring region 34, the surrounding portion through which the irradiation light of the decoloring light from the decoloring light source 8 cannot be blocked cannot be blocked. The degree of shielding was incomplete in that the region 34 had an opening to the outside.

  If there is a member that transmits the near infrared rays of the LED 26 and is resistant to heat, such a member can be arranged in the opening to increase the degree of shielding of the entire decoloring region 34. As a result of investigation, it was found that there was a suitable material called quartz glass.

  Quartz glass has a near infrared transmittance of 95% including a wavelength of 850 nm, which is the emission wavelength of the LED 26 of this example. That is, the near-infrared transmittance can be suppressed to a loss of 5%. Moreover, the heat-resistant temperature of quartz glass is 1200 degreeC. Such a high temperature does not occur in any part of the erasing apparatus.

  From the viewpoint of both light transmittance and heat resistance, quartz glass can be said to be a material that can sufficiently withstand use in order to shield the opening of the decolored portion. Therefore, it was decided to use quartz glass to shield the opening of the decoloring part.

  FIG. 12 is a cross-sectional view illustrating a configuration of a decoloring unit of the decoloring apparatus according to the third embodiment. The decoloring section 40 shown in the figure is the same as that of the second embodiment except for the quartz glass plates 37 (37a, 37b) and the quartz glass holding structure 38 (38a, 38b). FIG. 12 shows the edge of the heat insulating support member 36 by broken lines.

  As shown in FIG. 12, the decoloring part 40 of this example includes a quartz glass plate 37 (with an opening 39 (39a, 39b) of the decoloring region 34 held by a quartz glass holding structure 38 (38a, 38b). 37a and 37b) are shielded from the outside.

  Specifically, the quartz glass plate 37 is a natural quartz glass plate (Shin-Etsu Glass Co., Ltd.) having a thickness of 2 mm. However, the quartz glass is not limited to this, and any material that satisfies the above-described light-transmitting and heat-resistant conditions such as Pyrex (registered trademark) (Shot) and Tempax (Corning) can be substituted.

  FIG. 13 (a) is a graph showing the temperature transition of each part of the three temperature measurement fixed points of the metal frame at the control temperature of 400 ° C. in the configuration of the decoloring part 40 shown in FIG. Each part has a temperature of 40 ° C. or less, which is slightly lower than the decoloring part 10 (opening ratio: 40% to 50%) and the decoloring part 30, and is good in terms of temperature. .

  FIG. 13B shows the power in a stable state of the erasing unit 40 at the control temperatures of 350 ° C. and 400 ° C. when only the heater unit of the erasing unit 40 is driven and when the erasing process is being performed. It is a graph which is obtained from the measurement at 450 ° C. and is shown together with the power in a stable state when only the heater section of the decoloring section 10 and the decoloring section 30 is driven.

  In the graph shown in FIG. 13B, the experimental value of the heater power consumption value when only the heater is driven at the control temperature of 400 ° C. is 483.4 W in the decoloring section 40, 611.0 W in the decoloring section 30, and the decoloring section. 10 (opening ratio: 40% to 50%) was 719 W.

  That is, compared to the heater power consumption value 719 W of the basic configuration of the color erasing unit 10, the color erasing unit 40 of this example is 483.4 W, which is a decrease of about 235 W. In addition, it is 528.7 W at the time of driving while executing the decoloring process, which is a considerably low power value.

  During this experiment, yellowing of the paper due to heat was observed when erasing was performed at a control temperature of 400 ° C. Furthermore, as a result of experiments, it was confirmed that at 350 ° C., yellowing does not occur on the paper and the erasability does not deteriorate. That is, it has been found that the paper heating efficiency is increased when the erasing unit 40 is configured.

  As a result, the heater temperature setting at the time of color erasing can be lowered from the basic configuration of 400 ° C. to 350 ° C., and it has been found that further power reduction can be achieved. In actual measurement, the heater power consumption at 350 ° C. is 378.7 W when only the heater is operating, and 428.1 W when the color is erased.

  As described above, according to the third embodiment, the power consumption of the heater can be reduced to 600 W or less. Therefore, even if the erasing apparatus of this example is integrated with a printer, the power consumption is reduced to an office or the like. The power consumption can be reduced to less than the usable power. Furthermore, it is possible to reduce the influence of the temperature increase inside the heater.

  In this way, heat loss due to convection, radiation, and heat conduction can be minimized and power consumption can be reduced, resulting in low power consumption. An image forming apparatus can be provided.

  INDUSTRIAL APPLICABILITY The present invention can be used for a decoloring apparatus effective in reducing power consumption, that is, reducing power consumption by minimizing heat loss due to convection, radiation, and heat conduction.

DESCRIPTION OF SYMBOLS 1 Decoloring apparatus 2 Main body housing | casing 3 Paper conveyance path | route 4 (4a, 4b) Conveyance roller and roller body 5 Paper feed cassette 6 Paper storage cassette 7 (7a, 7b) Thermal radiation heater part 8 (8a, 8b) Decoloring light source 9 (9a, 9b) Erasing unit 10 Erasing part 11, 12 Bottom plate 13 Conveying roller pair 14 Feeding path 15 Drive roller 16 Driven roller 17 Pressing roller 18 Thin belt 19 Paper side edge conveying device 20 Paper 21 (21a, 21b ) Heater contact prevention wire 22 (22a, 22b) Wire holder 23 Heater contact prevention mechanism 25 Light source unit frame 26 LED
27 Lens 28 Heater 29 Heater holding bracket member 30 Decoloring part 31 (31a, 31b) Thermal radiation heater part 32 (32a, 32b) Thermal radiation surface 33 First heat insulation part 34 (34a, 34b) Decoloring area 35 Second Insulating part 36 Insulating support member 37 (37a, 37b) Quartz glass plate 38 (38a, 38b) Quartz glass holding structure 39 (39a, 39b) Opening

Claims (5)

A heat radiation heater that heats the print surface of the decolorizable toner image of the paper disposed above and below the paper conveyance path to decolorize the decolorizable toner image printed on both sides of the paper,
A decoloring light source that is disposed above and below the sheet conveyance path and that emits decoloring light to the printing surface of the decolorizable toner image of the sheet heated by the thermal radiation heater;
A first heat insulating portion that thermally seals a portion other than the heat radiation surface of the heat radiation heater from the outside;
A second surrounding the periphery of the decoloring region that receives the heat radiation of the heat radiation heater and the irradiation of the decoloring light of the decoloring light source, except the periphery through which the irradiation light of the decoloring light of the decoloring light source passes. Heat insulation part,
A heat-resistant translucent glass plate that is provided in the periphery through which the irradiation light of the decoloring light of the decoloring light source passes and shields the decoloring region from the outside in cooperation with the second heat insulating portion. When,
A decoloring device comprising:   2. The erasing apparatus according to claim 1, wherein the erasing light source comprises an LED (light emitting diode) that emits near infrared rays.   The decoloring apparatus according to claim 1, wherein the heat-resistant and translucent glass plate is made of quartz glass.   The said 1st heat insulation part consists of an inorganic fiber type heat insulating material, and surrounds and forms so that the outer surface of parts other than the said heat radiation surface of the said heat source may be solidified, The consumption of Claim 1 characterized by the above-mentioned. Color device.   The erasing apparatus according to claim 1, wherein the second heat insulating portion is made of a plate-like member of an inorganic fiber heat insulating material.