JP5659730B2 - Erasing device - Google Patents

Description

  The present invention relates to a decoloring apparatus, and more particularly, to a decoloring apparatus that is mounted on, for example, a rewritable printer and decolorizes a decolorable toner image with low energy consumption and quickly rising.

  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.

  There is also a method of using a heat-sensitive decoloring agent and decoloring with a heating oven type decoloring apparatus. There is also known a method of erasing the decolored toner using a part of light energy. However, when these erasing devices are installed in an office, an erasing device is required in addition to a printing device such as a printer, so that power is also required, and an installation space for the erasing device is also required. It is an economy.

  In addition, many decoloring apparatuses are not easy to use and are not always convenient for users because they require a long time for decoloring. From this point of view, it is desirable that the erasing apparatus is incorporated in another apparatus such as a printer so that printing with the erasable toner and erasing can be performed in addition to normal printing.

  For example, the function of performing development, transfer, and fixing using a decolorable toner to print on a recording sheet, and the decoloring toner characters and images printed on the recording sheet There has been proposed an image forming apparatus having a function of erasing light by irradiating light. (For example, refer to Patent Document 1.)

  Many examples are also shown regarding the erasing toner and the erasing apparatus. Among them, there is an apparatus that dramatically improves the decoloring speed by heating a printed image of a toner using a sensitizing dye and a boron compound that can be decolored by infrared rays and then decoloring by infrared rays. Proposed. (For example, see Patent Document 2.)

  In this apparatus, many light sources such as halogen, flash and LED lamps are effective as the light source for erasing, and many examples of halogen lamps are shown. In addition, since the halogen lamp also emits energy in a long wavelength region centering on far infrared rays, it is also used as a heat source. Only the heat source has been shown to be effective as a heat source for the purpose of assisting the decoloring reaction.

Japanese Patent Laid-Open No. 08-152823 Japanese Patent Laid-Open No. 05-204278

  By the way, in the prior art disclosed in Patent Document 1, the effectiveness of a printer in which the erasing device and the printing device are integrated to perform erasing and printing in the same device is shown. However, in that case, it is desired to reduce the total power consumption by adding the power consumption of the erasing unit in addition to the power consumption of the printer main body. However, there is no description about the problem of power consumption.

  In the prior art disclosed in Patent Document 2, the halogen lamp is light including not only the near infrared rays but also the ultraviolet region, the visible light region, and the near infrared region to the far infrared region. Therefore, not only the absorption wavelength of the sensitizing dye but also many extra wavelengths of energy that do not contribute to other decoloring reactions are radiated, which is an uneconomic energy source.

  Patent Document 2 shows the effectiveness of applying light in a state where the resin is heated to a temperature equal to or higher than Tg. In heating using a halogen lamp, a line is formed on a sheet passing through the conveyance path. It is not necessarily an advantageous means in terms of power consumption to install the lamp in a shape because the filament of the halogen lamp becomes longer and power consumption inevitably increases.

  In addition, when a halogen lamp is used, the lamp is always turned on during decoloring, and the lamp itself is a consumable that can be cut off in thousands of hours, resulting in a higher running cost.

  As for light sources other than halogen lamps, there is a description of LED as a light source type as an example, but there is no description about setting of the light source under specific decoloring conditions. In addition, since there has been no proposal for more effective light energy among such combinations of light sources and decoloring toners, the relationship between appropriate light and effective decoloring effect of the dye remains unclear.

  SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described conventional problems, and to provide a decoloring device that is mounted on a rewritable printer or the like and that has low energy consumption and quick start-up for decoloring a decolorable toner image. And

  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. An upper thermal radiation heater and a lower thermal radiation heater for heating the printing surface of the chromatic toner image, and an upper erasing light source and a lower erasing light source for irradiating the printing surface of the erasing toner image on the heated paper with the erasing light. A color light source, and the upper heat radiation heater and the lower heat radiation heater can be moved to a position where each heat dissipation surface approaches or contacts and a position where the heat radiation surface is opened when the color is erased. Composed.

  In this erasing apparatus, for example, the upper heat radiant heater or the lower heat radiant heater starts to generate heat at a position where the respective heat dissipation surfaces are close to or in contact with each other, and the heat generation temperature is decolored of the erasable toner image. When the temperature is suitable for the color, it is configured to move to the opening position at the time of executing decoloring.

  In this case, heat generation at a position where the heat dissipation surface is close to or in contact may be started simultaneously in the upper heat radiation heater and the lower heat radiation heater, for example, or, for example, the upper heat radiation heater. Alternatively, the lower heat radiation heaters may be alternately and exclusively started.

  In this decoloring apparatus, the thermal radiation heater is, for example, a ceramic heater, and the decoloring light source is, for example, an LED.

  The present invention can provide a decoloring device that is mounted on, for example, a rewritable printer or the like and decolorizes a decolorable toner image with low energy consumption and quick start-up.

It is sectional drawing which shows typically the internal structure of the color image forming apparatus provided with the erasing apparatus which concerns on Example 2 of this invention. FIG. 10 is a perspective view illustrating a paper both-side end conveyance device that constitutes a part of a conveyance mechanism of a decoloring apparatus according to Embodiment 2. 6 is a plan view of a transport mechanism of a decoloring apparatus according to Embodiment 2. FIG. (a) is a figure which shows the basic composition of the decoloring unit which concerns on Example 3, (b) is the top view, (c) is a figure which shows the structural example of the thermal radiation heater. (a), (b) is the figure which shows the closed state in the power-on test for the upper and lower thermal radiation heaters of the decoloring unit according to the third embodiment, divided into two examples: a proximity state and a contact state. It is a figure which shows the open state at the time of decoloring execution for a comparison. 10 is a chart showing test results of power-on for the upper and lower heat radiation heaters of the decoloring unit according to Example 3. It is a figure which shows the other example of the decoloring unit which concerns on Example 4 of this invention. It is a figure which shows the other example of a thermal radiation heater which concerns on Example 5 of this invention.

  Hereinafter, embodiments of the present invention will be described in detail. In the description of the present invention, “print” and “print” are used interchangeably as synonyms.

<Method for producing decolorizable toner>
First, a method for producing a decolorizable toner used in the present invention will be described as Example 1. First, 1.5 parts by mass of infrared photosensitive dye “IRT” (manufactured by Showa Denko) having sensitivity at 817 nm, 4 parts by mass of organic boron compound decolorizer “P3B” (manufactured by Showa Denko), polyester binder for toner 90.5 parts by mass of resin (manufactured by Kao), 1.5 parts by mass of negative charge control agent “LR-147” (manufactured by Nippon Carlit), 2.5 parts by mass of Carnauba WAX No. 1 powder (imported by Kato Yoko Co., Ltd.) Into a Henschel mixer (Mitsui Mine) and mix.

  Subsequently, the above mixture is melt-kneaded with a twin-screw kneader. The kneaded material thus obtained is roughly crushed with a Rotoplex (manufactured by Hosokawa Micron) to obtain a coarsely crushed material. The obtained coarsely crushed material is pulverized with an impact pulverizer and a classifier IDS / DSX (NPK) so that the average particle diameter becomes 9 μm.

  One part by mass of silica “R972” (manufactured by Nippon Aerosil Co., Ltd.) as an external additive is added to 100 parts by mass of the pulverized product obtained by this pulverization, and mixed with a Henschel mixer to obtain the decolorizable toner R.

  The erasing device is installed in the lower part of a normal electrophotographic printer. As will be described in detail later, the paper printed with the erasable toner and passed through the erasing device is warmed while passing under a heat source such as a ceramic heater, and in that state is erased by a light source such as an LED. Irradiated with colored light.

  Thereafter, printing on the decolored paper is executed by the same development, transfer, and fixing processes as those of a normal printer. The upper printer is not particularly limited as long as it can set the decoloring toner in the developing unit. Desirably, the erasing device and the printer are preferably integrated, but the erasing device may be installed independently from the printer. In the following description, it is assumed that the erasing apparatus is integrated with the printer.

<Printer structure>
FIG. 1 is a cross-sectional view schematically showing an internal configuration of a color image forming apparatus including a decoloring apparatus according to Embodiment 2 of the present invention.

  An image forming apparatus (hereinafter simply referred to as a printer) 1 shown in FIG. 1 includes an endless transfer belt 3 that extends in the horizontal direction at the center of the inside of a main body housing 2. The transfer belt 3 is stretched by a tension mechanism (not shown), is stretched around the drive roller 4 and the driven roller 5, is driven by the drive roller 4, and circulates in a counterclockwise direction indicated by an arrow a in the drawing. .

  Four image forming units 6 (6r, 6y, 6c, 6m) are provided above the upper circulation movement 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 (hereinafter referred to as a sheet) conveyed along the image forming conveyance path 12.

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

  The sheet 14 that has passed the secondary transfer portion while transferring the image of the decolorizable toner 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 paper 14 and convey it while applying heat and pressure.

  Accordingly, the sheet 14 is formed on the upper surface of the main body housing 2 by fixing the image of the erasable toner that has been secondarily transferred to the sheet surface and further transported by the heating roller 18 and the pressing roller 19. The paper is discharged onto the paper discharge tray 21.

  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. The erasing device 24 is provided with a transport mechanism and a erasing unit, which will be described in detail later. The erasing apparatus 24 shown in FIG. 1 shows only a sheet conveying path 25 of the conveying mechanism and two sets of sheet conveying roller pairs 26 (26a, 26b) that carry the sheet 22 into and out of the erasing apparatus 24. .

<Paper transport mechanism of erasing device>
When the color erasable toner image is printed on both sides of the paper 22, if the paper 22 is conveyed through the erasing device 24 by the belt conveying mechanism as usual, the toner on the back side melted by the heat for erasing. Adheres to the belt. Therefore, it is necessary to perform non-contact conveyance.

  Further, since the heating of the paper is high temperature, the paper is curled and there is a concern about contact with the heater. Further, there is a concern that the paper may come off without entering the downstream conveying roller pair 26b due to the rounding of the paper. Therefore, a transport mechanism that takes these into consideration is required.

  FIG. 2 is a perspective view showing a paper both-side end conveying device constituting a part of the conveying mechanism of the erasing device 24 of this example. In the figure, the upstream conveying roller pair 26a and the downstream conveying roller pair 26b are not shown.

  As shown in FIG. 2, on both sides of the paper transport path 25, a thin belt 31 having a pressing roller 29 at the center in the middle is placed between the driving roller 27 and the driven roller 28, and the both side edges of the paper are arranged. A transport device 32 is arranged. As shown in the figure, the sheet both-side end conveying device 32 conveys the sheet 22 in the direction of the arrow d in FIG.

  FIG. 3 is a plan view of the transport mechanism of the decoloring device 24 described above. As shown in FIG. 3, six heater contact prevention wires 33 (33a, 33b) are respectively provided above and below the paper 22 shown in FIG. 2 conveyed by the conveying roller pair 26a, 26b and the paper both-side edge conveying device 32. Is stretched (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 33a and 33b are respectively held by wire holding portions 34 (34a, 34b), constitute a heater contact prevention mechanism 35, and are fixedly arranged in the decoloring device 24.

  These heater contact prevention wires 33 (33a, 33b) prevent the sheet 22 from coming into contact with a heat radiation heater, which will be described later, and suppress the rounding of the sheet 22 from above and below, so that the sheet 22 is conveyed to both ends of the sheet conveyance device 32. To prevent it from falling off.

  Since these heater contact prevention wires 33 are stretched obliquely with respect to the conveyance direction of the paper 22 and are arranged at a wide interval, the erasing radiation heating from the thermal radiation heater described later and this will also be described later. It can be said that there is no blocking of the decoloring irradiation light from the LED light source.

  As described above, the paper transport mechanism of the erasing apparatus 24 of this example is configured by the two pairs of paper transport rollers 26 (26a, 26b), the paper both-side end transport device 32, and the heater contact prevention mechanism 35. Yes.

<Erasing unit of erasing device>
FIG. 4A is a diagram illustrating a basic configuration of a decoloring unit according to the third embodiment disposed above and below a paper transport path 25 configured by a paper transport mechanism of the decoloring device 24. FIG. ) Is a plan view thereof, and FIG. 8C is a diagram showing a configuration example of the heat radiation heater.

  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 wire holding portion 34 of the heater contact prevention mechanism 35 and the paper both-side end conveyance device 32 are not shown.

  4A and 4B, the decoloring unit 36 (36a, 36b) includes a heat radiation heater 37 (37a, 37b), a light source 38 (38a, 38b), and a lens 39 (39a, 39b). And a decoloring light source 41.

  The thermal radiation heater 37 is a ceramic type heater. Specifically, it is a ceramic heater made by NGK Kiln Tech. The product name Infrastein B (100 V / 200 W) was used in a triple. The total power used is 600W.

  As shown in FIG. 4 (c), the heat radiation heater 37 has a heat insulating structure in which a heat insulating layer 41 is formed inside the back surface that is opposite to the heat irradiation surface including the heat generating portion 41. Thereby, thermal radiation can be efficiently radiated from the heat irradiation surface.

  The thermal radiation heater 37 was used for testing purposes, and the length and width dimensions of one heater in the three-unit arrangement are 125 mm × 65 mm. The total length is 125 × 3 = 375 (mm) due to the triple connection, which greatly exceeds the A4 size paper width of 297 mm.

  However, when used as a heat radiation heater mounted on the decoloring device 24, the power consumption can be further reduced by downsizing according to the paper width.

  Moreover, although the ceramic heater was used in this test, it is not restricted to this. For example, a carbon heater can be used. In any case, it is desirable to irradiate radiant heat having a wavelength of 2 μm or more.

  While the surface of the paper 22 on which the color-erasable toner image is formed is heated by the heat radiation of the heat-radiation heater 37, the heat-radiation heater 37 is radiated from the color-erasing light source 41 to the paper surface being heated. It is installed obliquely at an angle of about 30 degrees with respect to the paper transport path 25.

  At this time, it is installed so that the end of the end closer to the paper transport path 25 has a height of 20 mm and the end of the far end has a height of 50 mm. In this state, the power is turned on, and when the surface of the heat radiation heater 37 generates heat at about 450 ° C., the condition suitable for decoloring is set.

  The light source 38 of the decoloring light source 41 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. Preferably, when the light around 820 nm, which is the first absorption band, can be irradiated at the center, the decolored light becomes efficient.

  The light source 38 of this example uses an LED as a power-saving light source. As the LED, 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 are arranged in a direction orthogonal to the paper passing direction, and a lens 39 having a focal length of 30 mm is arranged in front of these LEDs to constitute a decoloring light source 41. The lens 39 is a SELFOC lens (Nippon Sheet Glass trademark).

  The decoloring light source 41 is installed so that the paper 22 passing between the upper and lower thermal radiation heaters 37 can be irradiated with a width of about 150 mm from a distance of about 150 mm.

  Further, in order to efficiently irradiate the paper surface being heated by the heat radiation heater 37 with the decoloring light, the decoloring light 42 is applied to the paper at an angle of about 30 degrees from an oblique position with respect to the paper transport path 25. . At this time, the conveyance speed of the sheet as a decoloring condition was 15 mm / sec.

  At the time of erasing, as described with reference to FIG. 1, the paper 22 on which the image of the erasable toner is printed and discharged onto the paper discharge tray 21 is used. In this case, plain paper may be used as the paper 22 and is not particularly specified.

  However, in this example, P paper (64 g / m ^ 2) manufactured by Xerox Co., Ltd. with a clear standard was used as the decoloring evaluation paper in order to know the test results. A 1 cm square patch of a solid image having a C density of about 0.8 was printed on this paper. A colorimeter (X-rite 938) was used for measuring the C density. In addition, a text chart of about 10 fonts was printed for visual confirmation along with the printing of the patch. Note that the printed image with the decoloring toner is a bluish image.

  In the configuration of the erasing apparatus 24 described above, a numerical value obtained by measuring the patch after erasing with the Xrite 938 is taken as a measured value, the C density before erasing is about 0.8, and the C density after erasing is 0. The condition of about 1 was the temperature condition of the heat radiation heater 37, the installation condition of the decoloring light source 41, and the overall setting condition.

  Under the above-described erasable apparatus conditions, the heat radiation heater 37 shown in FIG. 4 takes in the erasing light of the erasing light source 41 for erasing into the heating paper, so that one side, that is, the side of the erasing light source 41 is larger. It becomes an open structure.

  In this state, when the temperature of the heat radiation heater 37 with power consumption of 600 W is turned on at the same time, the temperature rise time for starting up to a temperature at which the surface can be heated to about 450.degree. Second.

  Similarly, when the upper and lower thermal radiation heaters 37 are open, the upper and lower thermal radiation heaters 37 are heated to power by exclusively applying power to only one of the upper and lower thermal radiation heaters 37 in order to suppress peak power when the power is turned on. Did not reach the target temperature even after 20 minutes.

  Here, as a result of various studies, when the temperature of the heat radiation heater 37 is raised, the surface temperature of the heat radiation heater 37 can be quickly brought up to a temperature at which decolorization can be started at about 450 ° C. The inventor came up with the idea that the radiation heaters 37a and 37b may be closed.

  FIGS. 5 (a) and 5 (b) are diagrams showing the closed state divided into two examples: a proximity state and a contact state in a test in which power is turned on with the upper and lower thermal radiation heaters 37a and 37b closed. FIG. 8C is a diagram showing an open state when performing decoloring for comparison.

  FIG. 6 is a chart showing the test results described above. In addition, the condition column 44 of the chart 43 of FIG. 6 has shown the control conditions of power activation. That is, it is shown that the upper and lower thermal radiation heaters 37a and 37b are simultaneously powered on, or exclusively one of them is powered on.

  The start-up column 45 in the decolored state shows an evaluation result when the power is turned on with the upper and lower thermal radiation heaters 37 opened up and down before starting the test described below.

  As a condition for closing the upper and lower heat radiation heaters 37a and 37b, an energy saving effect can be obtained by closing at a position as close as possible to the paper rather than an open installation position which is a condition at the time of decoloring.

  Desirably, the gap between the upper and lower thermal radiation heaters 37 is set to 5 mm or less as shown in FIG. By doing so, convection of air is suppressed and loss at the time of temperature increase is reduced. When 600 W was simultaneously turned on in the proximity state at intervals of 5 mm, it was possible to start up in 4 minutes as shown in the row above the proximity installation column 46 in the chart 43 of FIG.

  More preferably, the heat radiation surface of the heat radiation heater 37 is brought into a contact state as shown in FIG. In this case, the heater contact preventing wire 33 seems to be an obstacle when the two heat radiation heaters 37 come into contact with each other, but it can be dealt with by forming a groove corresponding to the wire on the surface of the heat radiation heater 37.

  And in this contact state, as shown in the upper line of the contact installation column 47 of the chart 43 of FIG. 6, it was able to start up in 3 minutes and 40 seconds. As described above, in any case, the temperature can be raised in a short time, and the power consumption can be reduced.

  Further, in order to suppress the peak power consumption when the power is turned on, when the upper and lower heat radiation heaters 37 are exclusively turned on, the heat radiation of the upper and lower heat radiation heaters 37 is the same as described above. The rising state was examined when the surfaces were brought close to each other and brought into contact with each other.

  Then, in the proximity state at intervals of 5 mm, as shown in the row below the proximity installation column 46 in the chart 43 of FIG. In the contact state at intervals of 0 mm, as shown in the line below the contact installation column 47 in the chart 43 of FIG.

  In addition, as the power-on control in the case where only one of the above powers is turned on, for example, first, the lower heat radiation heater 37b is turned on, the upper heat radiation heater 37a is turned off, The heat radiation heater 37b is set to the set condition temperature, and then the lower heat radiation heater 37b is turned off and the upper heat radiation heater 37a is turned on to the set condition temperature.

  The rise times of 9 minutes 10 seconds and 8 minutes 40 seconds are obtained by repeating exclusive on / off of the power supply to the upper and lower thermal radiation heaters 37, respectively. In such repeated ON / OFF of the input power source, the energization timing of the upper heat radiation heater 37a and the lower heat radiation heater 37b can be arbitrarily set.

  In this way, when the power is turned on with the upper and lower thermal radiation heaters 37 in the proximity installation or contact installation state, the power is turned on simultaneously as compared with the case where the power is turned on while the upper and lower thermal radiation heaters 37 are opened in the decolored state. When the power is turned on, the rise is accelerated to about 2/3 or less, or about 1/2. In addition, even when exclusive power is turned on, it starts up in less than 1/2 time.

  After starting up as described above, the upper and lower thermal radiation heaters 37 are opened obliquely up and down to the state of decoloring while supplying electric power for maintaining the temperature of those radiation surfaces at about 450 ° C., Perform erasing.

  As described above, according to the erasing apparatus 24 of this example, it is possible to shorten the rise time and reduce the power consumption without changing the erasing function of the erasing unit.

<Other examples of erasing unit>
FIG. 7 is a diagram illustrating another example of the decoloring unit according to the fourth embodiment of the present invention. In FIG. 7, the same components as those shown in FIG. 3 are denoted by the same reference numerals as those in FIG. Further, in FIG. 7, illustration of the wire holding portion 34 of the heater contact prevention mechanism 35 and the paper both-side end conveyance device 32 is omitted.

  The arrangement of the decoloring unit shown in FIG. 7 with respect to the paper transport path 25 is the arrangement of the heat radiation heater 37 and the decoloring light source 41 of the decoloring unit 36 according to the third embodiment shown in FIGS. 4 (a) and 4 (b). Is replaced with the upstream side and the downstream side in the transport direction.

  Even if the heat radiation heater 37 and the color erasing light source 41 are arranged in this way, there is no change in the color erasing unit erasing function. In this case as well, the upper and lower heat radiation heaters 37 (37a, 37b) are in close proximity when the power is turned on. Alternatively, the power can be turned on after the contact state to shorten the rise time and reduce the power consumption.

<Other examples of thermal radiation heater>
FIG. 8 is a view showing another example of opening of the heat radiation heater according to the fifth embodiment. When the upper heat radiation heater 37a and the lower heat radiation heater 37b described above are opened from the proximity state or the contact state to the decoloring state, as shown in FIG. Good.

  Opening in parallel in this way has the effect of eliminating unevenness due to position in the heat radiation to the paper. However, since the distance from the paper is increased as a whole, it is not necessarily preferable from the viewpoint of thermal efficiency.

  In any case, when 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 determined to be either the upper side or the lower side. Since it has to be accommodated with the orientation set, it becomes inconvenient. 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 decolored simultaneously, so that good decoloring performance is maintained without degrading the decoloring performance, and the decoloring time is ½ compared to the case where the front and back decoloring processing is performed twice. Reduced to:

  The present invention can be used for a decoloring apparatus that is mounted on a rewritable printer or the like and that decolors a decolorable toner image with low energy consumption and quick start-up.

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 Follower roller 29 Pressing roller 31 Thin belt 32 Paper both-end conveying device 33 (33a, 33b) Heater contact prevention wire 34 (34a, 34b) Wire holding part 35 Heater contact prevention mechanism 36 (36a, 36b) Decoloring unit 37 (37a, 37b) Thermal radiation heater 38 (38a, 38b ) Light source 39 (39a, 39b) Lens 40 Groove 41 Decolored light source 42 Decolored light 43 Chart 44 Condition column 45 Startup column in decolored state 46 Proximity installation column 47 Contact installation column

Claims (5)

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, and an upper decoloring light source and a lower decoloring light source that irradiate decoloring light to the printing surface of the decolorable toner image of the heated paper,
The upper heat radiant heater and the lower heat radiant heater can move to a position where each heat dissipation surface is close or in contact and a position where the heat dissipation surface is opened when performing decoloring. Heat generation starts at the contact position, and when the heat generation temperature reaches a temperature suitable for erasing of the erasable toner image, it moves to a position to be opened when erasing is performed.
Erasing device characterized in that. Fever, the starts simultaneously in the upper heat radiant heater and the lower heat radiation heater, the erasing apparatus according to claim 1, wherein the at position where the heat dissipation surface is close to or in contact. Heating, the upper heat radiant heater or the lower heat radiant heater is initiated exclusively alternately, erasing apparatus according to claim 1, wherein the at position where the heat dissipation surface is close to or in contact. 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, and an upper decoloring light source and a lower decoloring light source that irradiate decoloring light to the printing surface of the decolorable toner image of the heated paper,
The upper heat radiant heater and the lower heat radiant heater can be moved to a position where each heat dissipating surface comes close to or in contact with the position where the heat radiating surface is opened when performing decoloring, and the heat radiant heater is a ceramic heater. is there,
Erasing device characterized in that. 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, and an upper decoloring light source and a lower decoloring light source that irradiate decoloring light to the printing surface of the decolorable toner image of the heated paper,
The upper heat radiant heater and the lower heat radiant heater can be moved to a position where each heat dissipating surface is close or in contact with a position where the heat radiating surface is opened at the time of decoloring,
The decoloring light source is an LED.
Erasing device characterized in that.