JP5585419B2 - Erasing device - Google Patents

Description

  The present invention relates to a color erasing apparatus, and more particularly to a color erasing apparatus that is mounted on a rewritable printer or the like and is effective for increasing the temperature of a sheet, lowering the heat source, reducing power consumption, and shortening the startup time.

  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 it is reused as a raw material, energy and cost are required for the recovery itself, and energy is also applied when it is processed as a 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, and can be mounted on, for example, a rewritable printer, and prevents toner offset, raises the temperature of the paper, lowers the heat source, reduces power consumption, and starts up. An object of the present invention is to provide an erasing device effective for shortening the time.

  In order to solve the above-described problems, first, the decoloring apparatus according to the first aspect of the present invention is the above-described paper disposed respectively above and below the paper transport path so as to erase the color-erasable toner images printed on both sides of the paper. An upper thermal radiation heater and a lower thermal radiation heater for heating the printing surface of the decolorable toner image, and an upper decoloring light source for irradiating the printing surface of the decolorable toner image of the heated paper with the decoloring light And the lower thermal radiation light source, and the upper thermal radiation heater and the lower thermal radiation heater have a thermal radiation surface from a portion parallel to the conveyance path and a portion parallel to the conveyance path on the upstream side of the conveyance path, respectively. An inclined portion that gradually separates from the conveyance path is continuously formed in a downstream direction of the conveyance path, and the upper decoloring light source and the lower decoloring light source are heat radiations of the upper heat radiation heater and the lower heat radiation heater. Surface from the transport path The surface of the transport path corresponding to the inclination start portions of the inclined portion away people in configured to be set on the upstream side irradiation region of the decoloring light.

  Next, the erasing apparatus according to the second aspect of the invention is the erasable toner image of the paper disposed above and below the paper transport path to erase the erasable toner images printed on both sides of the paper. An upper thermal radiation heater unit and a lower thermal radiation heater unit for heating the printing surface of the printer, and an upper decoloring light source and a lower decoloring light source for irradiating the decoloring light to the printing surface of the decolorable toner image of the heated paper The upper heat radiation heater part and the lower heat radiation heater part are respectively arranged so as to be inclined so that the heat radiation surface is gradually separated from the conveyance path from the upstream side to the downstream side of the conveyance path. The heater is interposed between the upstream end of the heat radiating surface of the heater and the conveying path, and conducts heat at the end of the heat radiating surface of the heater to be carried into the conveying path. A heat transfer auxiliary roller for preheating the paper to be The upper decoloring light source and the lower decoloring light source are formed on the surface of the transport path located on the downstream side of the upper heat radiation heater unit and the lower heat radiation heater unit, which are close to the heat conduction auxiliary roller. The upstream irradiation area is set.

  The present invention can be mounted on, for example, a rewritable printer, and has an effect that it is possible to provide a decoloring apparatus effective for increasing the temperature of a sheet, lowering the heat source, reducing power consumption, and shortening the startup time. .

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. (a) is a side view showing a basic internal configuration of the decoloring apparatus according to Embodiment 1, and (b) is a plan view thereof. It is a side view which shows the internal structure which improved the malfunction which arises partially in the basic structure shown in Example 1 of the erasing apparatus which concerns on Example 2. FIG. It is a side view which shows the internal structure which added the improvement further to the heat source of the decoloring apparatus which concerns on Example 3. FIG. It is a side view of an internal configuration showing another example of improvement added to the heat source of the decoloring apparatus according to Embodiment 4.

  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 drawing, illustration of the conveyance roller / roller body 26a on the upstream side in the sheet conveyance direction and the conveyance roller / roller body 26b on the downstream side is omitted.

  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. 4A is a diagram showing a basic configuration of the erasing unit of this example arranged above and below the paper transport path 25 constituted by the paper transport mechanism of the erasing device 24. FIG. FIG.

  4 (a) and 4 (b), the same components as those shown in FIG. 3 are given the same reference numerals as those in FIG. 4A and 4B, the heater contact prevention mechanism 35 and the paper both-side end conveyance device 32 are not shown.

  As shown in FIGS. 4A and 4B, the decoloring device 24 is provided above and below the paper transport path 25 from a heat radiation heater 36 (36a, 36b) and a decoloring light source 39 (39a, 39b), respectively. An erasing unit 40 is provided.

  The thermal radiation heater 36 is a ceramic heater. The heat radiation heaters 36 are arranged above and below the paper transport path 25 on the upstream side of the paper transport path 25 with the paper transport path 25 interposed therebetween. In order to improve the heat radiation efficiency to the paper transport path 25, the paper transport path 25 is arranged in parallel.

  The decoloring light source 39 includes a light source 37 (37a, 37b) and a lens 38 (38a, 38b). The light source 38 of this example uses an LED as a power-saving light source. As the LED, an 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 preferable.

  Fifteen LEDs are arranged in a direction orthogonal to the paper passing direction (only five are shown in FIG. 4B), and a lens 38 having a focal length of 30 mm is arranged in front of these LEDs to provide a decoloring light source 40. Are arranged so that the irradiation light 41 hits the entire sheet width Pw.

  In order to irradiate the decoloring light 41 onto the paper being heated by the thermal radiation heater 36, that is, to irradiate the decoloring light 41 between the upper and lower thermal radiation heaters 36, the decoloring light source 40 is directed to the paper conveyance path 25. The decoloring light 41 is disposed obliquely.

  The lens 38 disposed between the light source 37 and the paper transport path 25 is linear so that the decoloring light 41 of the light source 37 can be condensed with respect to the paper traveling direction to effectively irradiate the decoloring light 41. Fresnel lens is used.

  In the above configuration, the dimensions and arrangement relationships of the respective parts are as follows: the width Hw of the heat radiation heater 36 is 60 mm, the distance D between the heat radiation heater 36 and the paper transport path 25 is 20 mm, and the paper transport speed is 15 mm / sec.

  By the way, in order for the decoloring light 41 of the decoloring light source 39 to obtain effective decoloring with respect to the decoloring toner image, the paper, that is, the decoloring toner image needs to have an appropriate temperature. The appropriate temperature of this paper is about 200 ° C. Therefore, the temperature setting for the heat radiation heater 36 requires a temperature setting of 320 ° C. in the above arrangement relationship.

  Further, in order to effectively erase the color erasable toner image while preventing destruction of the color erasing agent of the color erasable toner image, the temperature of the paper (hereinafter, paper = color erasable toner image) is erased. In a range where the decoloring light 41 is applied to the paper before reaching a suitable temperature and the decoloring light 41 hits, it is efficient that the paper is maintained at a suitable temperature.

  That is, point e is the point at which the temperature of the sheet being conveyed through the sheet conveyance path 25 reaches an appropriate temperature, point f is the point where the temperature of the sheet deviates from the appropriate temperature, point g is upstream of the irradiation surface 42 of the decoloring light 41, and point downstream. As shown in FIG. 4B, these relationships are expressed in the order of g point, e point, h point, and f point from the upstream side (left side of the drawing) of the sheet transport path 25, as shown in FIG. It is desirable to become.

  In the case of the dimensions and arrangement of each part described above, the distance j from the left end surface i of the heat radiation heater 36 to the point e is about 30 mm, and the distance k from the left end surface i of the heat radiation heater 36 to the point f is about 30 mm. 80 mm.

  However, in this configuration, as shown in FIG. 4A, the portion corresponding to the point g on the upstream side of the irradiation surface 42 of the decoloring light 41 from the decoloring light source 39 is on the downstream side of the heat radiation heater 36. Is blocked by the end of the paper and cannot reach the paper transport path 25. This cannot provide an efficient decoloring action.

  When the distance D between the heat radiation heater 36 and the paper transport path 25 is increased in order to solve this problem, it is necessary to set the set temperature of the heat radiation heater 36 significantly high, which is not realistic.

  As described in Example 2, the basic configuration of the color erasing device 24 will be described below as an example in which a problem that partially occurs in the irradiation of the color erasing light 41 when the heat radiation heater 36 is arranged in parallel to the paper conveyance path 25 is improved. explain.

  FIG. 5 is a side view illustrating an internal configuration of the erasing apparatus 24 according to the second embodiment. In the case of this example as well, the configuration of the main body of the printer 1 including the appearance of the decoloring device 24 shown in FIG. 1, the configuration of the paper both-end conveying device 32 and the heater contact prevention mechanism 35 shown in FIG. Is the same as in Example 1.

  In the internal configuration of the erasing apparatus 24 of the present example, as shown in FIG. 5, the erasing unit 43 is obliquely arranged such that the heat radiation heater 36 is lifted upward with respect to the sheet conveying path 25 in the sheet conveying direction. It is arranged.

  In this state, the distance E from the upstream end of the heat radiation heater 36 to the paper transport path 25 is set to 20 mm, and the distance F from the downstream end of the heat radiation heater 36 to the paper transport path 25 is set to 30 mm. .

  Thus, in the relationship between the paper transport path 25 and the irradiation surface 42 described above, the relevant points of each main part can be set in order of the g point, the e point, the h point, and the f point from the upstream side. It was possible to perform effective decoloring without disturbing.

  By the way, the temperature setting of the heat radiation heater 36 in this case requires about 400 to 450 ° C. From the viewpoint of safety, reduction of power consumption, and shortening of start-up time, it is a concern that the set temperature of the heat radiation heater 36 is lowered to a temperature setting equal to or lower than the parallel arrangement of the heat radiation heater 36.

  FIG. 6 is a side view illustrating the internal configuration of the decoloring apparatus according to the third embodiment. In this example as well, the configuration of the main body of the printer 1 including the appearance of the erasing device 24 shown in FIG. 1, the configuration of the paper both-end conveying device 32 and the heater contact prevention mechanism 35 shown in FIG. This is the same as the case of 1. In this example, the heat source is further improved.

  That is, as shown in FIG. 6, in the decoloring unit 44 of this example, the upper and lower heat radiation heaters 36 are parallel portions whose heat radiation surfaces are parallel to the paper transport path 25 on the upstream side of the paper transport path 25. 45-1 and an inclined portion 45-2 that is gradually separated from the paper transport path 25 in the downstream direction of the paper transport path 25 from the parallel portion 45-1 are continuously formed.

  These upper and lower heat radiation heaters 36 are so-called bent shapes, and are arranged so as to be rotated to the left and right so that one straight line of the character is horizontal.

  The decoloring light 41 emitted from the upper and lower decoloring light sources 39 respectively conveys the paper corresponding to the inclination start portion of the inclined portion 45-2 where the heat radiation surface of the heat radiation heater 36 gradually moves away from the paper conveyance path 25. An upstream irradiation area is set on the surface of the path 25 (the above-mentioned g point).

  In the heat radiation heater 36 of this example, in the parallel portion 45-1, the sheet is maintained at a suitable temperature up to point e in FIG. 6 at a set temperature equivalent to that of the heat radiation heater 36 of FIG.

  The inclined portion 45-2 radiates heat so as to maintain an appropriate temperature for the sheet up to point f in FIG. With this, in the relationship between the paper transport path 25 and the irradiation surface 42 shown in FIG. 4B, it is possible to realize that the relevant points of each main part are in the order of g point, e point, h point, and f point from the upstream side. Thus, effective decoloring could be performed without hindering the irradiation of the decoloring light 41.

  FIG. 7 is a side view illustrating the internal configuration of the decoloring apparatus according to the fourth embodiment. In this example, the configuration of the printer 1 main body device including the appearance of the erasing device 24 shown in FIG. 1 and the configuration of the paper both-end conveying device 32 shown in FIG. 2 are the same as those in the first embodiment. The heater contact prevention mechanism 35 shown in FIG. 3 is removed because it is not used.

  In this example, another example different from FIG. 6 of the improvement point added to the heat source is shown. That is, as shown in FIG. 7, the decoloring unit 46 in the decoloring device 24 of this example forms a heat radiation heater section 51 with a heat radiation heater 48 and a heat conduction auxiliary roller 49.

  The heat radiation heater 48 is disposed so as to be inclined so that the heat radiation surface 47 gradually moves away from the paper transport path 25 from the upstream side to the downstream side of the paper transport path 25. The heat radiation heater 48 is the same heater as the heat radiation heater 36 shown in FIG.

  The heat conduction auxiliary roller 49 is interposed between the upstream end portion 47-1 of the heat radiation surface 47 of the heat radiation heater 48 and the paper transport path 25. The heat conduction auxiliary roller 49 is provided so as to be close to the heat radiation heater 36.

  The heat conduction auxiliary roller 49 is provided with an elastic heat-resistant roll 53 using a material having elasticity and heat resistance, for example, glass wool, porous silicon rubber, etc. around the core metal 52, and the outer periphery of the heat conduction auxiliary roller 49 has heat conductivity. A high metal film is used, and a Teflon (registered trademark) tube for preventing image offset is provided on the outer side.

  The heat conduction auxiliary roller 49 is heated by the heat radiation heater 36, and is configured to heat the paper by a contact method with high thermal efficiency. The paper heated to near the proper temperature for erasing by the heat conduction auxiliary roller 49 is then maintained at the proper temperature from the point e to the point f by the heat radiation heater 36 and heated to maintain the optimum temperature from the point e. The

  The configuration and arrangement of the upper and lower decoloring light sources 39 (39a, 39b) are the same as those in FIG. Also in this example, the point g of the upstream irradiation region of the decoloring light 41 emitted from the upper and lower decoloring light sources 39 is located on the downstream side in the vicinity of the heat conduction auxiliary roller 49 and upstream of the point e. Is set to the paper transport path 25 located at the position.

  Thus, also in the configuration of this example, it is possible to set the relevant points of each main part in the order of g point, e point, h point, and f point from the upstream side, without disturbing the irradiation of the decoloring light 41, Effective decoloring was possible.

  Thus, in the above-described third embodiment, a heat source bent into a square shape is used, and in the fourth embodiment, the heat conduction auxiliary roller is used, and the toner image is heated to the appropriate temperature for the decoloring light irradiation by heating the paper. Since the sheet being heated is irradiated with the decoloring light when it reaches, the relationship between the effective heating and the light irradiation to the decolorable toner image can be ensured.

  Therefore, since the temperature rise effect on the paper can be increased, there is no waste in radiant heat radiation of the heat source, and the set temperature of the heat source can be lowered. Thereby, the effect that safety, reduction of power consumption, and shortening of start-up time can be obtained.

  The present invention can be used, for example, in a decoloring apparatus that is mounted on a rewritable printer or the like and is effective for increasing the temperature of a sheet, lowering the heat source, reducing power consumption, and shortening the startup time.

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 14 sheet 15 upper sheet cassette 16 fixing conveyance path 17 fixing unit 18 heating roller 19 pressure roller 21 sheet discharge tray 22 sheet 23 lower sheet feeding cassette 24 decoloring device 25 sheet conveyance path 26 (26a, 26b) sheet conveyance roller pair 27 Drive roller 28 Followed roller 29 Pressing roller 31 Thin belt 32 Paper both-end conveyance device 33 (33a, 33b) Heater contact prevention wire 34 (34a, 34b) Wire holding part 35 Heater contact prevention mechanism 36 (36a, 36b) Thermal radiation heater 37 (37a, 37b) Light source 38 (38a, 38b) Len 39 (39a, 39b) Decoloring light source 40 Decoloring unit 41 Decoloring light 42 Irradiation surface 43, 44 Decoloring unit 45-1 Parallel portion 45-2 Inclined portion 46 Decoloring unit 47 Thermal radiation surface 47-1 Upstream end 48 heat radiant heater 49 heat conduction auxiliary roller 51 heat radiant heater 52 cored bar 53 elastic heat resistant roll

Claims (2)

An upper thermal radiation heater and a lower portion for heating the printing surface of the decolorizable toner image of the paper respectively disposed above and below the paper conveyance path to decolorize the decolorable toner image printed on both sides of the paper A heat radiation heater;
An upper erasing light source and a lower erasing light source for irradiating the printing surface of the decolorable toner image of the heated paper with decoloring light;
With
The upper heat radiant heater and the lower heat radiant heater each have a heat radiating surface on the upstream side of the transfer route and a portion parallel to the transfer route and a portion parallel to the transfer route toward the downstream side of the transfer route. Consecutive slope part gradually away from the path,
The upper decoloring light source and the lower decoloring light source are provided on the surface of the conveyance path corresponding to the inclination start portion of the inclined portion where the heat radiation surfaces of the upper heat radiation heater and the lower heat radiation heater are gradually separated from the conveyance path. , An upstream irradiation area of the decoloring light is set,
A decoloring device characterized by that. An upper thermal radiation heater unit for heating the printing surface of the decolorizable toner image of the paper disposed above and below the conveyance path of the paper to decolorize the decolorable toner image printed on both sides of the paper; A lower heat radiation heater,
An upper erasing light source and a lower erasing light source for irradiating the printing surface of the decolorable toner image of the heated paper with decoloring light;
With
The upper heat radiation heater part and the lower heat radiation heater part are respectively arranged with a heater so that the heat radiation surface is inclined so as to gradually move away from the transport path from the upstream side to the downstream side of the transport path; The sheet that is interposed between the upstream end of the heat radiation surface of the heater and the transport path, conducts heat of the end of the heat radiation surface of the heater, and is carried into the transport path. A heat conduction auxiliary roller for preheating,
The upper decoloring light source and the lower decoloring light source are disposed on the surface of the transport path located on the downstream side of the upper heat radiation heater unit and the lower heat radiation heater unit that are close to the heat conduction auxiliary roller. The upstream irradiation area is set,
A decoloring device characterized by that.