JP5505050B2 - Multifunctional image forming apparatus with toner decoloring function - Google Patents

Description

  The present invention relates to a multifunctional image forming apparatus with a toner erasing function capable of forming an image of a erasable toner on a printing medium and erasing an image on the printing medium formed of the erasable toner.

  Conventionally, a decolorable toner using a near-infrared photosensitive dye is used, and light is emitted from a decoloring light source to reuse the paper on which an image is formed with the decolorable toner. A decoloring apparatus that performs decoloring is known (for example, see Patent Documents 1 and 2).

  There is also known an erasing and image forming apparatus in which a erasing light source is incorporated in a conventional printer, not as a dedicated erasing apparatus (see, for example, Patent Documents 3, 4, 5, and 6).

  At the time of erasing, the printed matter is heated by heat from a heater incorporated in the apparatus, and the printed matter is irradiated with light from a light source for erasing. In such an apparatus, a heater and a light source are installed in the paper path. When a paper already printed with the decoloring toner passes through the path, the paper is heated by the heater to emit light. It has a mechanism to irradiate.

  On the other hand, in recent years, there is an apparatus called MFP (Multi Function Peripheral or Multi Function Printer) that also functions as a printer, a scanner, a copier, and a FAX (for example, Patent Literature) 7, 8).

  Further, as a technique related to the present invention, a technique using a ceramic heater for the purpose of improving thermal efficiency with respect to a fixing device of an image forming apparatus is disclosed (for example, see Patent Document 9).

JP 2000-081816 A Japanese Patent Laid-Open No. 07-175379 JP 05-289575 A JP 05-289576 A JP 07-096434 A Japanese Patent Application Laid-Open No. 07-199753 JP 2000-057842 A JP 2008-067213 A Japanese Patent Laid-Open No. 06-075491

  However, when the printed matter is heated at a high temperature of 130 ° C. to 420 ° C. as in the prior art of Patent Document 1, a temperature rise in the apparatus main body and a large power consumption are required. The problem is a major problem in printer design. However, this problem has a problem that Patent Document 1 is left unsolved without any description.

  Each of the preceding examples basically uses a halogen lamp as a light source for erasing. In general, it is well known that halogen lamps have a wide range of wavelength distribution. Therefore, the halogen lamp also emits a wavelength unnecessary for decoloring. There is a problem that problems such as a rise in temperature in the apparatus main body due to generation of light having a wavelength unnecessary for decoloring and large power consumption remain unsolved.

  Further, the decoloring and image forming apparatus disclosed in Patent Documents 3, 4 and 6 is based on the premise of two light sources, ie, a light source for irradiating a document and a light source for decoloring, and there is a problem to be solved that the configuration is complicated. is there.

  Further, although the multifunctional image forming apparatus disclosed in Patent Document 7 or 8 has a multifunctional type, the multifunctional image forming apparatus does not have a function of forming an image with a decolorable toner on a print medium. There is a problem to be solved that there is no function for erasing the image on the print medium formed by the above, and that the multifunctional type is somewhat inferior in function.

  In addition, the image fixing apparatus disclosed in Patent Document 9 uses a ceramic heater that has been developed in recent years. However, the image recording apparatus originally has only a fixing device that requires heat. There is no idea that the ceramic heater is used for other components other than the image fixing device.

  The present invention solves the above-described conventional problems, and is a toner decolorization capable of forming an image with a decolorable toner on a print medium and capable of decoloring an image on the print medium formed with the decolorable toner. An object is to provide a multifunctional image forming apparatus with functions.

In order to solve the above problems, a multifunctional image forming apparatus with a toner erasing function according to the present invention includes a document conveying unit and a light irradiation that irradiates a predetermined light beam on an image surface of the document conveyed by the document conveying unit. And an image reading unit that reads an image of the original, and an image forming unit that forms an erasable toner image or a normal toner image on a sheet by an electrophotographic method. A multifunctional image forming apparatus with a toner erasing function having a toner erasing function for erasing the erasable toner image formed thereon via the image reading unit, wherein the light irradiation means the light source is composed of elongated LED array comprising individual chips independently lighting controllable plurality of LED chips comprises at least three primary colors LED chip, the light irradiation means, the original When reading the image surface, illuminating the original with white light by simultaneously lighting the three primary color LED chips of the long LED array, and erasing the image formed on the paper with the decolorable toner Selectively illuminates a predetermined LED chip among the plurality of LED chips of the long LED array, and irradiates a surface of the sheet on which the image is formed with a predetermined long wavelength light. When irradiating the light of the long wavelength, the amount of power supplied to the LED chip that emits the light of the long wavelength is increased to increase the amount of light of the LED chip, compared to the case of irradiating the white light. It is characterized by that.

It said light irradiating means, for example, as light of said predetermined long wavelength is irradiated with light having a center wavelength of 817Nm, characterized and this.

  In this multifunctional image forming apparatus with a toner erasing function, for example, the image reading unit having the toner erasing function is an image reading of an existing ADF (Automatic Document Feeder) of an MFP (Multi Function Peripheral or Multi Function Printer). It is replaced with a part and is arranged.

  The present invention has an effect that a multifunctional image forming apparatus with a toner erasing function can be provided by a slight mechanism design change to an existing MFP.

1 is a cross-sectional view illustrating an internal configuration of a multifunctional image forming apparatus (MFP) with a toner erasing function according to Embodiment 1 of the present invention. 2A and 2B are external perspective views of the MFP according to the first embodiment, in which FIG. 1A is a diagram viewed from the diagonally upper right direction in FIG. 1, and FIG. 1 is a circuit block diagram including a control device of an MFP according to Embodiment 1. FIG. (a) is a figure explaining the structure and operation | movement of the reading and erasing part of MFP which concerns on Example 1, (b) is a figure which shows the lens structure of a LED light source and a reading part, (c) is a basic of LED light source It is sectional drawing which expands and shows a structure typically. 6 is a wavelength comparison diagram with a halogen lamp for explaining the light emission characteristics of a red LED chip having a center wavelength approximate to near-infrared light in the LED light source of the MFP according to Embodiment 1. FIG. 6 is a diagram for explaining light emission control of an LED light source employed in the MFP according to Embodiment 1. FIG.

  Hereinafter, embodiments of the present invention will be described in detail.

FIG. 1 is a cross-sectional view illustrating an internal configuration of a multifunctional image forming apparatus with a toner erasing function (hereinafter simply referred to as MFP) according to a first embodiment of the present invention.
2A and 2B are external perspective views of the MFP. FIG. 2A is a diagram seen from the upper right side of FIG. 1, and FIG. 2B is an oblique left side of FIG. It is the figure seen from.

  As shown in FIGS. 1 and 2A and 2B, the MFP 1 includes an image forming unit 2 and an image scanner unit 3.

First, the image forming unit 2 will be described.
The image forming unit 2 is an electrophotographic and secondary transfer tandem color image forming apparatus, and includes an image forming unit unit 4, an intermediate transfer belt unit 5, a paper feeding unit 6, a duplex printing transport unit 7, and electrical equipment. The unit 10 is configured.

  The image forming unit 4 has a configuration in which four image forming units 8 (8M, 8C, 8Y, 8K) are arranged in a multistage manner from right to left in FIG.

  Of the four image forming units 8, three image forming units 8M, 8C, and 8Y on the upstream side (right side in the figure) are magenta (M), cyan (C), and yellow (subtractive three primary colors), respectively. A monocolor image is formed with the color toner of Y).

  The most downstream image forming unit 8K can be replaced with the image forming unit 8R by opening the front door FD shown in FIGS. 2 (a) and 2 (b). The image forming unit 8R is used solely and forms a decolorable toner image with the decolorable toner (R).

  Since the decolorizable toner is well known, the description of the method for producing the decolorable toner is omitted here.

  When used alone, the image forming unit 8K forms a black and white image, and when used together with the three image forming units 8M, 8C, and 8Y, the image forming unit 8K is mainly used for dark portions of characters and images. (K) A monochrome image is formed with toner.

  Each of the image forming units 8 has the same configuration except for the color of the toner stored in the toner container (toner cartridge). Therefore, the configuration of the image forming unit 8K for black (K) will be described below as an example.

  The image forming unit 8 includes a photosensitive drum 9 at the bottom. The photosensitive drum 9 has a peripheral surface made of, for example, an organic photoconductive material. A cleaner 11, a charging roller 12, an optical writing head 13, and a developing roller 15 of a developing device 14 are arranged around the periphery of the photosensitive drum 9.

  In the upper toner container, the developing unit 14 is magenta (M), cyan (C), yellow (Y), black (K) or decolored as indicated by M, C, Y, and K (R) in FIG. One of the toners (R) is accommodated, and a toner replenishing mechanism for the lower part is provided in the middle part.

  Further, the developing roller 15 is provided in the lower side of the developing unit 14 at the side opening, and a toner stirring member, a toner supply roller 16 for supplying toner to the developing roller 15, and a toner layer on the developing roller 15 are fixed. A doctor blade that regulates the layer thickness is provided.

  The intermediate transfer belt unit 5 has an endless transfer belt 17 that extends in a flat loop shape from substantially the left and right sides of the drawing at approximately the center of the main body device, and the transfer belt 17 is stretched over the transfer belt 17. A driving roller 18 and a driven roller 19 are provided to circulate and move the belt 17 counterclockwise in the figure.

  The transfer belt 17 directly transfers the toner image onto the belt surface (primary transfer) and conveys the toner image to the transfer position to the paper for further transfer (secondary transfer). The whole is called an intermediate transfer belt unit.

  The intermediate transfer belt unit 5 includes a belt position control mechanism 21 in the loop of the flat loop-shaped transfer belt 17. The belt position control mechanism 21 includes a primary transfer roller 22 made of a conductive foam sponge that presses against the lower peripheral surface of the photosensitive drum 9 via the transfer belt 17.

  The belt position control mechanism 21 includes three primary transfer rollers 22 corresponding to the three image forming units 8M, 8C, and 8Y of magenta (M), cyan (C), and yellow (Y) with a bowl-shaped support shaft. Rotate to the center with the same period.

  Then, the belt position control mechanism 21 sets one primary transfer roller 22 corresponding to the image forming unit 8K or 8R of black (K) or decolorizable toner (R) to the cycle of the three primary transfer rollers 22. The transfer belt 17 is moved away from and in contact with the photosensitive drum 9 by rotating at different rotation movement cycles.

  That is, the belt position control mechanism 21 determines the position of the transfer belt 17 of the intermediate transfer belt unit 5 in the full color mode (all four primary transfer rollers 22 are in contact with the transfer belt 17), monochrome mode, or decoloring toner mode. (Only the primary transfer roller 22 corresponding to the image forming unit 8K or 8R is in contact with the transfer belt 17) and all non-transfer modes (all four primary transfer rollers 22 are separated from the transfer belt 17).

  In the intermediate transfer belt unit 5, a belt cleaner unit is disposed further upstream of the uppermost image forming unit 8 </ b> M in the belt moving direction on the upper surface, and is flat and thin so as to be almost along the entire lower surface. The waste toner collecting container 23 is detachably disposed.

  The paper feed unit 6 includes two paper feed cassettes 24 arranged in two upper and lower stages, and in the vicinity of the paper feed opening (right side of the drawing) of the two paper feed cassettes 24, respectively, A feeding roller 26, a separating roller 27, and a standby conveying roller pair 28 are disposed.

  In the paper conveyance direction (vertical upward direction in the figure) of the standby conveyance roller pair 28, a secondary transfer roller 29 that is in pressure contact with the driven roller 19 via the transfer belt 17 is disposed, and a secondary transfer portion to the paper is arranged. Forming.

  A belt-type heat fixing device 31 is disposed on the downstream side (upper side in the drawing) of the secondary transfer unit, and on the further downstream side of the belt-type heat fixing device 31, the sheet after fixing is belt-type heat fixing device 31. A pair of carry-out rollers 32 for carrying out the paper and a pair of paper discharge rollers 34 for discharging the carried paper to a paper discharge tray 33 formed on the upper surface of the apparatus are disposed.

  The duplex printing transport unit 7 includes a start return path 35a branched from the transport path from the carry-out roller pair 32 to the paper discharge roller pair 34 in the right lateral direction in the figure, an intermediate return path 35b bent downward, and the above. A terminal return path 35c that bends in the opposite left lateral direction and finally reverses the return sheet is provided.

  Further, the duplex printing transport unit 7 includes four pairs of return rollers 36a, 36b, 36c, and 36d arranged in the middle of the return path. The exit of the end return path 35 c communicates with a conveyance path to the standby conveyance roller pair 28 corresponding to the sheet feeding cassette 24 below the sheet feeding unit 6.

  The electrical component 10 includes a circuit board on which a control device, which will be described in detail later, is composed of a plurality of electronic components.

  In this example, a cleaning unit 37 is disposed on the upper surface of the intermediate transfer belt unit 5. The cleaning unit 37 comes into contact with the upper surface of the transfer belt 17 to scrape and remove the waste toner, and accumulates it in a temporary storage unit of a belt cleaner unit (not shown).

  Then, the cleaning unit 37 conveys the accumulated waste toner to the upper portion in the dropping cylinder by the conveying screw and sends it to the waste toner collecting container 23 through the dropping cylinder.

  As shown in FIG. 1, the image forming unit 2 does not directly transfer a toner image onto a conventional sheet, but an intermediate transfer belt on a sheet that is vertically conveyed by a standby conveying roller pair 28 to a secondary transfer unit. The toner image is transferred via the toner image 17.

  Therefore, during the maintenance process for recovering from a problem such as a paper jam occurring in the paper conveyance path, the intermediate transfer belt unit 7 is opened outward with a hinge (not shown) as a fulcrum, and the right side in FIG. It can be dealt with.

  In addition, since troubles such as paper jam do not occur in the arrangement section of the kits, the front door FD is opened when the consumables such as the kits concentrated on the left side of FIG. It is configured so that it is only necessary to replace a kit or a circuit board in the longitudinal direction.

  The image forming process in the image forming unit 2 is a normal electrophotographic toner image forming process (printing process), and can be switched between monochrome printing and decoloring toner printing. Except for this, there is no special processing, and thus the details of the image forming processing are omitted.

Next, the image scanner unit 3 will be described.
The image scanner unit 3 of this example has not only an image of a document but also a color erasing function for erasing a color erasable toner image formed on a sheet.

  The image scanner unit 3 includes a flat bed unit 38 and an ADF (Automatic Document Feeder) unit 39 as in a normal scanner. An original table made of a transparent glass plate is disposed on the upper surface of the flat bed portion 38.

  The lower surface of the paper discharge tray portion 42 of the ADF portion 39 is in contact with the upper surface of the flat bed portion 38 so as to be opened and closed. 2A and 2B, the handle 41 is lifted up by hand and the ADF unit 39 is rotated upward so that the engagement surface between the lower surface of the paper discharge tray unit 42 and the upper surface of the flat bed unit 38 is formed. When opened, the document table on the upper surface of the flat bed portion 38 is exposed.

  In addition, a sub-scanning direction scanning unit 43 including a belt with a blade and a shaft or a driving string and a rail is disposed on the inner bottom portion of the flat bed portion 38. In the sub-scanning direction scanning unit 43, a reading and erasing unit 44 composed of a long LED (light emitting diode) array and a long image sensor, which will be described in detail later, is movable to the left and right as indicated by a double-directional arrow a. Is retained.

  In addition, an operation panel 45 is disposed in front of the flat bed portion 38 as shown in FIGS. 2 (a) and 2 (b). The operation panel 45 includes a display unit 46 capable of touch input and a button unit 47 including a plurality of buttons capable of mechanical input on an upper surface inclined slightly downward.

  On the other hand, the ADF unit 39 includes a swivel conveyance unit 48 at the left end of the paper discharge tray unit 42. A paper feed tray 49 is attached to the swivel conveyance unit 48. The paper feed tray 49 is positioned above the paper discharge tray section 42 and is sufficiently spaced from the upper surface of the paper discharge tray section 42 so that a predetermined number of documents or sheets can be discharged and placed on the paper discharge tray section 42. Arranged.

  The paper feed tray 49 is provided with lateral width restricting plates 51 that can be arbitrarily moved in the lateral direction on both sides thereof. The document or paper placed on the paper feed tray 49 is regulated by the lateral width regulation plate 51 and is not skewed, and is fed to the swivel conveyance unit 48.

  As shown in FIG. 1, the swivel transport unit 48 contacts the paper feed belt 52 and the paper feed belt 52 provided at the paper feed end of the paper feed tray 49, and rotates in the reverse direction to feed the document or paper double. A roller 53 to be prevented and a standby roller pair 54 arranged downstream thereof are provided.

  Further, the swivel conveyance unit 48 is arranged at substantially equal intervals on the circumferential surface of the swivel conveyance roller 55 and the swivel conveyance roller 55 downstream of the standby roller pair 54, and is driven in pressure contact with the circumferential surface of the swirl conveyance roller 55. Three driven rollers 56 (56a, 56b, 56c) are provided.

  Further, the swivel transport unit 48 includes a long plate-shaped ceramic heater 57 disposed in contact with the peripheral surface of the swivel transport unit 48 between the first driven roller 56a and the second driven roller 56b. Yes. In general, ceramic heaters are known for their small size and high thermal efficiency.

  When the image of the erasable toner formed on the paper is erased by the reading and erasing unit 44, the ceramic heater 57 heats the erasable toner image on the paper before irradiating the color erasing light to read the image. It arrange | positions in order to assist the erasing by the cum erasing part 44.

  Further, the swivel transport unit 48 includes a pair of paper discharge rollers 58 disposed between the paper feed end of the paper feed tray 49 and the left end of the paper discharge tray unit 42 downstream of the third driven roller 56c. Yes.

  The reading and erasing unit 44 described above with this position as the home position at a position on the flat bed 38 side between the second driven roller 56b and the third driven roller 56c of the swivel conveying unit 48. Is arranged. In other words, the reading and erasing unit 44 of this example is arranged in place of the existing ADF image reading unit of the MFP.

Next, a control circuit including a control device stored in the electrical unit 10 of the MFP 1 having the above configuration will be described.
FIG. 3 is a circuit block diagram including the control device of the MFP 1.

  As shown in FIG. 3, the circuit block is centered on a central processing unit (CPU) 60, and an interface controller (I / F_CONT) 61, a printer controller (PR_CONT) 62, and a scanner are connected to the CPU 60 via data buses. A controller (SC_CONT) 63 is connected.

  A printer printing unit 64 is connected to the PR_CONT 62 described above. Although not particularly shown, the printer printing unit 64 is connected to a belt driving unit, a transport mechanism driving unit, an applied voltage output unit, and the like.

  Further, the SC_CONT 63 is connected to the image scanner unit 3 and the ceramic heater 57 shown in FIG. A reading and erasing unit 44 is connected to the image scanner unit 3, and an LED light source 65 and an image sensor 66 are connected to the reading and erasing unit 44.

  Also connected to the CPU 60 are a ROM (read only memory) 67, an EEPROM (electrically erasable programmable ROM) 68, an operation panel 45 of the main body operation unit, and a sensor unit 69 to which outputs from sensors arranged in each unit are input. Has been. The ROM 67 stores a system program, and the CPU 60 performs processing by controlling each unit according to the system program.

  That is, in each unit, first, the I / F_CONT 61 converts print data supplied from a host device such as a personal computer into bitmap data and develops it in the frame memory 71. In the frame memory 71, a storage area is set for each of black (K), magenta (M), cyan (C), yellow (Y), and decolorizable toner (R), and image data for each toner corresponds. It is expanded to the area to be.

  The data expanded in the frame memory 71 is output to the PR_CONT 62 and is output from the PR_CONT 62 to the printer printing unit 64.

  The printer printing unit 64 is an engine unit, and under the control of the PR_CONT 62, the rotational drive system including the photosensitive drum 9, the primary transfer roller 22 and the like shown in FIG. 1, the charging roller 12, the optical writing head 13, and the like. A drive output to a process load such as an applied voltage of an image forming unit having a driven portion is controlled.

  Further, although not shown in the drawing, the printer printing unit 64 includes a belt driving unit that performs the vertical movement of the intermediate transfer belt unit 5, the rotation driving of the transfer belt 17, the belt driving of the belt type fixing device 31, and the paper take-out roller 25. Controls drive output to a transport mechanism drive unit that drives a transport mechanism that is composed of various parts that are rotationally driven, such as the paper discharge roller pair 34.

  The data of each color of black (K), magenta (M), cyan (C), yellow (Y) or decolorable toner (R) output from the PR_CONT 62 corresponds from the printer printing unit 64, respectively. 1 is supplied to the optical writing head 21 shown in FIG.

  SC_CONT 63 indicates that when an original event is instructed by an input event output from operation panel 45, the original is placed on paper feed tray 49 according to a detection signal output from sensor unit 69, or It is checked whether the flatbed portion 38 is placed on the document table, the LED light source of the reading and erasing unit 44 is set to the reading mode, and each unit is controlled to execute reading of the document.

  When SC_CONT 63 is designated to be erased by an input event output from the operation panel 45, a sheet to be erased on which an image of a decolorable toner is formed is placed on the paper feed tray 49. The LED light source of the reading and erasing unit 44 is set to the erasing mode, the ceramic heater 57 is driven to generate heat, and the swivel conveying unit 48 is driven to control each unit to execute erasing. To do.

  FIG. 4A is a diagram for explaining the configuration and operation of the reading and erasing unit 44, FIG. 4B is a diagram showing the LED light source and the lens configuration of the reading unit, and FIG. It is sectional drawing which expands and shows a basic composition typically.

  As shown in FIG. 4A, the reading and erasing unit 44 includes a unit frame 72 having a flat U-shaped cross section, and a long LED fixedly attached to the unit frame 72. An LED light source 65 formed of an array, an SLA (Selfoc (registered trademark) lens array) 73, a CCD (Charge Coupled Device) chip 74 and an image sensor 66 formed of a substrate 75 are included.

  The operation relationship between the document 78 on the document table 77 and the reading and erasing unit 44 shown in FIG. 4A is that the document 78 is fixed when the document 78 is placed on the flat bed unit 38. The reading and erasing unit 44 moves to the left and right as indicated by the double arrow a shown in FIG.

  On the other hand, when the document 78 is placed on the paper feed tray 49, the reading and erasing unit 44 is fixed at the home position shown in FIG. 1, and the document 78 is swirled and transported by the swivel transport unit 48. It passes over the platen 77 corresponding to the position position.

  In either case, the light emitted from the LED light source 65 to the image forming surface of the document 78 via the document table 77 as indicated by the arrow b is reflected as indicated by the arrow c and enters the SLA 73.

  As shown in FIG. 4B, the LED light source 65 is a long LED array in which three primary color LED chips 79 (red 79r, green 79g, and blue 79b) are arranged on a long substrate 82, as will be described later. Each LED chip can be controlled to be turned on independently.

  In the figure, the arrangement of the LED chips is rough, but in actuality, they are arranged at the same density as the LED array of the optical writing head 13. However, it is an LED having a wide irradiation angle rather than an irradiation angle in an acute angle narrowed to a narrow range like the LED of the optical writing head 13.

  FIG. 4 (c) schematically shows the individual basic configuration of each of the three primary color LED chips 79, taking a single LED as an example. The LED shown in FIG. 4 (c) is a light emitting element in which one electrode is fixed to a terminal of two lead wires 82 (82a, 82b) and one lead wire 83a via a conductive adhesive 83. 84 and a gold wire 85 that connects the other electrode of the light emitting element 84 and the terminal of the other lead wire 83 b are embedded in the epoxy resin 86.

  Irradiation light due to light emission of the light emitting element 84 is irradiated from the radiation surface 87 of the epoxy resin 86 in a range that forms an obtuse angle with a spread width 88 (88a, 88b).

  By selecting the light emitting elements 84 of the plurality of LED chips having such a basic configuration, a linear light source in which the LED chips 79 including the light emitting elements 84 having a desired wavelength from a short wavelength to a long wavelength are arranged in a desired order can be obtained.

  For example, a white light source can be obtained by combining three-wavelength (three primary colors) LED chips of light-emitting elements 84 having different blue, green, and red colors. Further, light sources having different wavelengths can be obtained by controlling switching points of individual LED chips.

  Therefore, paying attention to this principle, in this example, by constructing an LED light source module that combines an LED chip (red 79r) having a central emission wavelength in the near infrared region on the red side and a wide half-value width, it can be used for document illumination. Is configured so that light irradiation with a center wavelength of, for example, 817 nm can be performed as white light and decoloring light.

  On the other hand, the SLA 73 shown in FIGS. 4 (a) and 4 (b) is a long plate-like lens array in which a large number of gradient index rod-shaped lenses are arranged, and an enlarged image of incident light is arranged at the bottom. Project to the image sensor 66.

  Thereby, the image in the main scanning direction of the document is read, and the image in the sub-scanning direction is read by relatively moving the document 78 and the reading and erasing unit 44.

  The MFP 1 of this example can copy characters and images read from the document 78 in the image forming unit 2 using the paper stored in the paper feed cassette 24.

  Further, in the image forming unit 2 using the paper stored in the paper feed cassette 24 based on image information including a print instruction command input by wire / wireless from a host device (not shown) such as a personal computer. Monochrome texts can be printed, and full-color images can be printed (hereinafter, including printing).

  In addition to monochrome printing and full-color printing, the image forming unit 8K and the image forming unit 8R are replaced and mounted, so that the paper stored in the paper feed cassette 24 is used to erase with the decolorable toner (R). A chromatic toner image can be formed.

  Then, after using the paper on which the erasable toner image is formed, the erasable toner image that is no longer necessary can be erased from the paper. When erasing the color, the paper is placed on the paper feed tray 49 of the ADF unit 39 of the image scanner unit 3 with the erasable toner image forming surface facing upward.

  When a decoloring instruction is input from the selection button displayed on the button unit 47 or the display unit 46 of the operation panel 45, the decoloring is started. In this case, the reading and erasing unit 44 shown in FIG. 4A is fixed at the home position shown in FIG.

  The paper 91 to be erased is swirled and transported by the swivel transport unit 48 and passes over the document table 77 corresponding to the home position. At this time, under the control of SC_CONT 63, the turning conveyance roller 55 rotates counterclockwise, and the ceramic heater 57 is driven to generate heat.

  The decolorizable toner forming the decolorable toner image on the paper 91 is softened by heating from the ceramic heater 57, and the decolorability by light irradiation is improved. The erasable toner image having improved erasability is irradiated with erasable light having a center wavelength approximate to near-infrared light from the red 79r LED chip of the LED light source 65 of the reading and erasing unit 44.

  FIG. 5 is a wavelength comparison diagram with a halogen lamp for explaining the light emission characteristics of a red 79r LED chip having a center wavelength approximate to near-infrared light in the configuration of the LED light source 65. As shown in the figure, the emission wavelength 92 of the halogen lamp has a wide wavelength distribution ranging from about 400 nm to over 1100 nm. For this reason, as described above, there are problems such as a rise in temperature in the apparatus main body due to generation of light having a wavelength unnecessary for decoloring and large power consumption.

  On the other hand, the red 79r LED chip having a central wavelength approximate to the near-infrared light of the LED light source 65 used in the first embodiment is configured by an LED array, and the other three primary color LED chips (green 79g, blue 79b). ) And switching can switch the light emission drive.

  As shown in FIG. 5, the emission wavelength 93 of the LED has a very narrow wavelength distribution. That is, the LED is considered to generate very little light having a wavelength unnecessary for decoloring depending on the selection. Also, LEDs are well known for their high efficiency of electricity / light conversion and not generating large heat.

  Therefore, in this example, in order to correspond to the infrared photosensitive dye that is also used for the three primary colors red and has a sensitivity to 817 nm of the decolorizable toner, a red 79r LED chip with a center wavelength of 830 nm having a slightly wide wavelength distribution at half width is used. The LED light source 65 is arranged side by side with the green 79g and the blue 79b.

  FIG. 6 is a diagram for explaining the light emission control of the LED light source 65 employed in this example. In FIG. 6, in order to easily understand the principle of control, the arrangement relationship of the document 78 (or paper 91), the LED light source 65, and the image sensor 66 is shown differently from the case of FIG.

  As shown in FIG. 6, a light emission drive wiring 94 is connected to each LED chip of the three primary color LED chips 79 of the LED light source 65. From the SC_CONT 63, a light emission drive wiring 94 to which power is supplied is selected by a light emission color switching signal 95 input to the LED light source 65 via the image scanner unit 3 and the reading and erasing unit 44.

  As a result, when reading the document 78, all the LEDs of the three primary color LED chips red 79r, green 79g, and blue 79b are driven to emit light, and white light is emitted from the LED light source 65 to the document 78. The reflected light is input to an image sensor 66 composed of a monochrome CCD, and a luminance signal 96 is output from the image sensor 66 to SC_CONT 63.

  The SC_CONT 63 generates the color tone and density of the image read from the document 78 by combining the time-division emission color switching signal 95 and the luminance signal 96 and notifies the CPU 60 of it.

  On the other hand, when erasing the erasable toner image on the paper 91 on which the erasable toner image is formed, a red 79r LED chip having a center wavelength approximate to near-infrared light is driven to emit light. At this time, the electric power supplied for the light emission driving is more than the power for driving the light emission of the three primary color LED chips 79r, 79g, 79b to emit white light, and the light quantity of the red 79r LED chip is increased. To increase.

  As shown in FIG. 4 (c), the irradiation angle of the light emitting element of the LED chip used in the LED light source 65 is wide and has a spread to irradiate the front area of one adjacent light emitting element. As a result, it is possible to erase the color-erasable toner image in the front area of the LED chips of green 79g and blue 79b that are not lit.

  The light emitting element of the red 79r LED chip used for the LED light source 65 has a center wavelength of 750 nm, and a near-infrared LED chip having a center wavelength of 817 nm and a half-value width of 50 nm is alternately arranged with the three primary color LED chips. It may be used while switching the drive side by side.

  The present invention is applicable to a multifunctional image forming apparatus with a toner erasing function capable of forming an image with a erasable toner on a print medium and erasing an image on the print medium formed with the erasable toner. Can do.

1 Multifunctional image forming device (MFP) with toner decoloring function
2 Image forming unit 3 Image scanner unit 4 Image forming unit unit 5 Intermediate transfer belt unit 6 Paper feeding unit 7 Double-sided printing transport unit 8 (8M, 8C, 8Y, 8K) Image forming unit 9 (7m, 7c, 7y, 7k) ) Photosensitive drum 10 Electrical section 11 Cleaner 12 Charging roller 13 Optical writing head 14 Developer 15 Developing roller 16 Supply roller 17 Transfer belt 18 Drive roller 19 Driven roller 21 Belt position control mechanism 22 Primary transfer roller 23 Waste toner collection container 24 Paper cassette 25 Paper take-out roller 26 Feed roller 27 Rolling roller 28 Standby conveyance roller pair 29 Secondary transfer roller 31 Belt-type heat fixing device 32 Unload roller pair 33 Paper discharge tray 34 Paper discharge roller pair 35a Start return path 35b Intermediate return Road 35c Terminal return path 36a, 36b, 36 36d Return roller pair 37 Cleaning unit 38 Flat bed unit 39 ADF (Automatic Document Feeder) unit 41 Handle 42 Paper discharge tray unit 43 Sub-scanning direction scanning unit 44 Reading and erasing unit 45 Operation panel 46 Display unit 47 Button unit 48 Turning Conveying section 49 Paper feed tray 51 Width regulating plate 52 Paper feed belt 53 Rolling roller 54 Standby roller pair 55 Revolving conveyance roller 56 (56a, 56b, 56c) Driven roller 57 Ceramic heater 58 Paper discharge roller pair 60 CPU (central processing unit)
61 Interface controller (I / F_CONT)
62 Printer controller (PR_CONT)
63 Scanner controller (SC_CONT)
64 Printer printing section 65 LED (light emitting diode) light source 66 Image sensor 67 ROM (read only memory)
68 EEPROM (electrically erasable programmable ROM)
69 Sensor unit 71 Frame memory 72 Unit frame 73 SLA (Selfoc (registered trademark) lens array)
74 CCD (Charge Coupled Device) chip 75 substrate 77 document table 78 document 79 three primary color LED chips 79r red 79g green 79b blue 81 long substrate 82 (82a, 82b) lead wire 83 conductive adhesive 84 light emitting element 85 gold wire 86 epoxy Resin 87 Radiation surface 88 (88a, 88b) Spreading width 89 Parallel light 91 Paper 92 Halogen lamp emission wavelength 93 LED emission wavelength

Claims (3)

Document conveying means;
Light irradiating means for irradiating a predetermined light beam on the image surface of the document conveyed by the document conveying means;
Reading means for reading an image of the document;
An image reading unit having
An image forming unit that forms a decolorable toner image or a normal toner image on a sheet by electrophotography;
Comprising at least
A multifunctional image forming apparatus with a toner erasing function having a toner erasing function for erasing the erasable toner image formed on the paper via the image reading unit,
Source of the light irradiation means is composed of an elongated LED array comprising at least three primary colors LED (light emitting diode) individual chips independently lighting controllable plurality of LED chips comprises chip,
The light irradiation means includes
When reading the image surface of the original, irradiate the original with white light by simultaneously lighting the three primary color LED chips of the long LED array,
When erasing the image formed on the paper with the decolorizable toner, a predetermined LED chip among the plurality of LED chips of the long LED array is selectively lit to have a predetermined long wavelength. The surface of the paper on which the image is formed is irradiated in a line with
When irradiating the long-wavelength light, the amount of power supplied to the LED chip that emits the long-wavelength light is increased to increase the amount of light of the LED chip than when irradiating the white light.
A multifunctional image forming apparatus having a toner erasing function. The light irradiation means, the light of the predetermined long wavelength is irradiated with light having a center wavelength of 817Nm, claim 1 Toner color erasing function multi-function image forming apparatus, wherein a.   The image reading unit having the toner erasing function is disposed in place of an existing ADF (Automatic Document Feeder) image reading unit of an MFP (Multi Function Peripheral or Multi Function Printer). 2. A multifunctional image forming apparatus with toner decoloring function according to 1.