JP2012032541A - Image forming apparatus with decoloring and gloss-imparting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus with a decoloring and gloss-imparting device, the apparatus capable of printing a color image and a color-fadable toner image, decoloring an image, and further imparting gloss to a normal toner image.SOLUTION: In a color image printing mode, a full-color toner image is formed by driving image forming units 6m, 6c, 6y of color toners of magenta, cyan and yellow, respectively, or additionally, an image forming unit 6k of a black toner, and then transferring the full-color toner image onto a recording medium 14 by use of a secondary transfer roller 12. In a monochromatic printing mode, a monochromatic image of the black toner or a color-fadable toner is formed by driving an image forming unit 6k or 6r of the black toner or a color fadable toner. In a decoloring mode, the color-fadable toner image on a recording medium 15 where the color-fadable toner image is printed is decolored by driving a decoloring heat source 27 in a decoloring unit 26 to generate heat and by driving a decoloring light source 28 to irradiate the image. In a gloss imparting mode, gloss is imparted to a toner image on the recording medium 15 where a normal toner image is printed, by driving only the decoloring heat source 27 of the decoloring unit 26 to generate heat.

Description

  The present invention is capable of printing a color image, printing with a color erasable toner, and color erasing the color erasable toner image, and imparting gloss to an image with a normal toner regardless of whether the toner is a mat type toner or a gloss type toner. The present invention relates to an image forming apparatus with a decolorizing and glossing device capable of performing the above.

  In recent years, particularly in printing of photographs and the like, glossy images have been favored as high-quality images with good quality. For this reason, various devices for increasing the gloss of the printed image on the printing apparatus side have been proposed. (For example, see Patent Documents 1, 2, and 3.)

JP 2007-333953 A JP 2004-139040 A JP 2002-304072 A

  However, the prior art disclosed in Patent Document 1 is a method of giving gloss to a printed image using a belt-type fixing device in an electrophotographic color image recording apparatus, but a sheet on the downstream side of the fixing nip portion. A cooling device is provided on the opposite side of the belt with respect to the conveyance path to cool the heat of the belt. This has a problem to be solved that the fixing device becomes large.

  In Patent Document 1 or 2, the fixing device is provided with two pairs of rollers. However, since the fixing unit is performed at the nip portion between the rollers, the fixing property to the sheet is insufficient. Further, since the interval between the two roller pairs is narrow, there is almost no cooling time from the upstream roller pair in charge of fixing to the downstream roller pair that applies heat and pressure to impart gloss. That is, there is no difference from the fixing operation when the fixing roller pair is one set, and the nip width should simply be widened.

  Originally, the toner is fixed on the sheet only after being cooled and solidified. In Patent Document 1 or 2, it is described that toner is first fixed on a sheet and then smoothness of the surface is secured. However, although cooling is required to fix the toner on the paper, there is no cooling period, so it is considered difficult to function as described.

  It is empirically known that, in order to increase the glossiness of an image, it is effective to further increase the smoothness of the surface once fixed. Normally, when trying to increase the glossiness by passing through a fixing device, it is necessary to perform both fixing to paper (adhering so as not to remove toner) and imparting smoothness to the toner formed on the paper at the same time. There is.

  However, the smoothness of the toner cannot be increased unless the toner is sufficiently melted. Also, if the pressure for pressing the toner against the paper is increased to increase the smoothness, the toner permeates into the paper, and the toner spills into the paper, reducing the amount of toner on the paper. . In such a state, the toner smoothness cannot be obtained because the amount of exposed toner is small.

  In order to avoid this state, it is conceivable to increase the amount of toner on the paper. However, as the amount of toner to be fixed increases, the amount of heat required for fixing becomes necessary, and it becomes difficult to achieve the temperature until the toner is sufficiently melted. For this reason, there arises a contradiction that the smoothness of the toner surface cannot be obtained.

  However, if the toner has already been sufficiently fixed as in a normal printed matter, it is heated to such an extent that the toner fixing property is not impaired, thereby improving the smoothness of the toner surface and increasing the glossiness. High gloss images as desired.

  In Patent Documents 1 to 3, a configuration is devised only to improve the smoothness of the toner surface and increase the glossiness during printing, and to impart gloss to the surface of a toner image that has been printed. Is not considered at all.

  The present invention solves the above-described conventional problems, and the gloss of the surface of a toner image on which printing has been completed without changing the normal fixing device, the normal color erasing unit, and other configurations. An object of the present invention is to provide an image forming apparatus with a color erasing and glossing device for imparting a color.

  In order to solve the above-described problems, an image forming apparatus with a decoloring and glossing device according to the present invention includes a color image printing mode, a monochromatic toner printing mode, a decoloring toner image decoloring mode, and normal toner printing. Mode switching means for switching the glossing mode to the finished image, and when the color image printing mode is switched, the magenta, cyan, yellow toner image forming unit, or the black toner image forming unit is driven. Full-color image printing means for printing a full-color image on a recording medium, and a black toner image forming unit or a black toner image forming unit that is replaced with a black toner image forming unit when switched to a mono-color toner printing mode. Black toner or erasability to the recording medium by driving the color toner image forming unit When the color erasing mode is switched to the erasing mode of the erasable toner image and the erasing mode of the erasable toner image, the erasing heat source of the erasing unit is driven to generate heat and the erasing of the erasing unit A erasable toner image erasing means for erasing the erasable toner image of the recording medium on which the erasable toner image is printed by irradiating and driving the illuminating light source; When switched, a recording medium on which a toner image has been printed is transported through the decoloring portion by driving the decoloring heat source of the decoloring unit to generate heat and prohibiting the irradiation driving of the decoloring light source of the decoloring unit. And a toner image gloss imparting means for imparting gloss to the toner image.

  The decoloring heat source of the decoloring unit is composed of, for example, a halogen light heater, a carbon heater, or a ceramic heater.

  The present invention provides an image forming with a decoloring / gloss imparting device that imparts gloss to the surface of a toner image on which printing has been completed without changing the normal fixing device, normal decoloring unit, and other configurations. An apparatus can be provided.

1 is a cross-sectional view schematically showing an internal configuration of a four-color tandem-type color image forming apparatus with a decoloring function equipped with a decoloring / gloss imparting apparatus according to Example 1 of the present invention. 1 is a circuit block diagram including a control device of a four-color tandem type color image forming apparatus with a decoloring function equipped with a decoloring / gloss imparting apparatus according to Embodiment 1. FIG. FIG. 10 is a cross-sectional view schematically illustrating only an essential part of an internal configuration of an image forming apparatus with a decoloring and gloss applying apparatus according to a second embodiment. (a), (b) is a figure explaining the decoloring efficiency and heating efficiency by arrange | positioning the decoloring unit in the point-symmetrical position with respect to a paper conveyance path | route like FIG.

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

  FIG. 1 is a cross-sectional view schematically showing an internal configuration of a four-color tandem type image forming apparatus with a color erasing / gloss imparting apparatus equipped with the color erasing / gloss imparting apparatus according to Embodiment 1 of the present invention. An image forming apparatus 1 with a decolorizing and glossing device shown in FIG. 1 includes an endless transfer belt 3 that extends in the horizontal direction at the center of the inside of 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, 6y, 6c, 6m) are disposed above the upper circulation movement surface of the transfer belt 3. Since these four image forming units 6 have the same configuration except for the color of the toner to be accommodated, only the image forming unit 6r will be described below.

  The image forming unit 6 includes a photosensitive drum 7. The photosensitive drum 7 is disposed in contact with the upper circulation moving surface of the transfer belt 3.

  A cleaner, an initialization charger, and an optical writing head (not shown) are arranged on the photosensitive drum 7 so as to surround the peripheral surface thereof, followed by a developing roller 8 and the like. ing. The developing roller 8 is disposed in the side opening of the toner container 9.

  In the case of the image forming unit 6r, the image forming unit 6r can be replaced with an image forming unit 6k in which normal black toner is stored in the toner container 9 as desired by the user.

  The developing roller 8 carries a thin layer of toner contained in a toner container 9 on its surface, and the toner is applied to the electrostatic latent image formed on the peripheral surface of the photosensitive drum 7 by an optical writing head. Develop the image.

  A primary transfer roller (not shown) is pressed against the lower portion of the photosensitive drum 7 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 in the primary transfer portion, and transfers the toner image developed on the peripheral surface of the photosensitive drum 7 to the transfer belt 3.

  A secondary transfer roller 12 is pressed against the driven roller 5 over which the right end portion of the transfer belt 3 shown in the figure is stretched, and forms a secondary transfer portion. A bias voltage is supplied to the secondary transfer roller 12 from a bias power source (not shown).

  The secondary transfer roller 12 applies a bias voltage supplied from a bias power source to the transfer belt 3 at the secondary transfer unit, and the toner image primarily transferred to the transfer belt 3 is indicated by an arrow b or an arrow c. Then, the image is transferred to the recording medium 14 or 15 conveyed.

  The recording medium 14 conveyed as indicated by the arrow b is stacked and accommodated in the upper paper feed cassette 16, taken out by the uppermost sheet by a paper feed roller (not shown), and indicated by the arrow b. In this way, the toner image is transferred to the paper feed conveyance path and transferred through the secondary transfer portion.

  The recording medium 14 that has passed the secondary transfer portion while transferring the toner image is conveyed along the fixing conveyance path 17 to the fixing portion 18. The heating roller 19 and the pressure roller 21 of the fixing unit 18 sandwich the recording medium 14 and convey it while applying heat and pressure.

  As a result, the secondary transfer toner image is fixed on the paper surface of the recording medium 14, and is further conveyed by the heating roller 19 and the pressing roller 21, so that a paper discharge tray formed on the upper surface of the main body housing 2 is formed. The paper is discharged to 22.

  On the other hand, the recording medium 15 conveyed as indicated by the arrow c is a recording medium on which a decoloring toner image has already been formed on the paper surface. The recording medium 15 is taken out from the lower sheet feeding cassette 23 one by one. As shown in d, it is sent out to the paper feed path.

  In this case, the recording medium 15 is carried into the decoloring / gloss applying device 24. In the decoloring / gloss applying device 24, a decoloring unit 26 is disposed above the paper transport path 25. The erasing unit 26 includes a erasing heat source 27 and a erasing light source 28.

  The decoloring heat source 27 of the decoloring unit 26 includes a reflecting plate 29 having a mirror surface with a parabolic cross section, and a halogen lamp 31 surrounded by the reflecting plate 29 in the side surface direction and the rear surface direction. . The decoloring light source 28 of the decoloring unit 26 includes an LED 32 and an LED holding unit 33 that holds the LED 32 as, for example, an LED array.

  Further, the recording medium 15 carried into the decoloring / gloss imparting device 24 is conveyed to the paper conveyance path 25 under the decoloring unit 26 and is discharged to the outside of the decoloring / gloss imparting device 24. Conveying roller pairs 34 (34a, 34b) are provided on the upstream side and the downstream side of the color unit 26, respectively.

  As the halogen lamp 31 of the erasing heat source 27, which is one configuration of the erasing unit 26, a halogen lamp that collects most of the energy in the vicinity of the wavelength of 1.3 μm of the spectrum of the emitted light is used. Efficient radiant heat is applied to the toner image recording medium.

  For the LED 32 of the erasing light source 28 which is the other configuration of the erasing unit 26, for example, an LED that emits light having a wavelength in the vicinity of 820 nm is used. Near-infrared light having a wavelength near 820 nm is a light beam having a wavelength that most efficiently erases the decolorizable toner.

  The decoloring / gloss imparting device 24 first warms the decolorable toner image on the recording medium 15 to a predetermined temperature by the decoloring heat source 27 and irradiates the decoloring toner image with the LED 32 of the decoloring light source 28. Discolor with light.

  The recording medium 15 from which the color erasable toner image has been erased is then transported along the transport path as indicated by arrows c and b, and a new toner image is passed through the secondary transfer portion as in the case of the recording medium 14. Transcribed.

  Regardless of whether the toner image to be transferred is the recording medium 14 or the recording medium 15, either a color image or a single color image is selected according to an instruction from the user or an instruction from the host device. .

  In the case of a color image, a color image using three image forming units 6y, 6c and 6m, or an image forming unit 6r of decolorable toner is replaced with an image forming unit 6k of black toner to form four images. A color image using the units 6k, 6y, 6c, and 6m is selected.

  Further, in the case of a single color image, the single color image by the decolorable toner only by the image forming unit 6r of the decolorable toner or the image forming unit 6r of the decolorable toner is replaced with the black toner image forming unit 6k. A black single-color image by only the black toner image forming unit 6k is selected.

  As described above, the four-color tandem type image forming apparatus 1 with a decoloring and glossing device includes a printing mode for printing a color image, a printing mode for printing a single color image, and a decoloring toner image. In addition to the color erasing mode, it further includes a gloss imparting mode for imparting gloss to the toner image of the recording medium 14 or 15 on which the toner image has been printed.

Here, the control device of the color image forming apparatus 1 with the erasing function of this example will be described.
FIG. 2 is a circuit block diagram including the control device of the four-color tandem type color image forming apparatus 1 with a decoloring function equipped with the decoloring and glossing device 24 of this example.

  As shown in FIG. 2, the circuit block has a CPU (central processing unit) 35 as a center, and an interface controller (I / F_CONT) 36 and a printer controller (PR_CONT) 37 are connected to the CPU 35 via data buses. ing. A printer printing unit 38 is connected to the PR_CONT 37.

  In addition, the CPU 35 has a ROM (read only memory) 41, an EEPROM (electrically erasable programmable ROM) 42, an operation panel 43 of the main body operation unit, a sensor unit 44 to which an output from a sensor arranged in each unit is input, and an eraser. A color / gloss imparting section 45 is connected.

  A system program is stored in the ROM 41, and the CPU 35 performs processing by controlling each unit in accordance with the system program.

  That is, in each unit, first, the I / F_CONT 36 converts print data (toner image print data) supplied from a host device such as a personal computer into bitmap data and develops it in the frame memory 46.

  In the frame memory 46, a storage area is set for each of the erasable toner R (or black toner K), the magenta toner M, the cyan toner C, and the yellow toner Y, and the data of each color corresponds to the corresponding area. Be expanded.

  The data developed in the frame memory 46 is output to the PR_CONT 37, and is output from the PR_CONT 37 to the printer printing unit 38.

  The printer printing unit 38 is an engine unit, and under the control of the PR_CONT 37, controls the driving output of a roller rotation driving system including the photosensitive drum 7, the primary transfer roller, the secondary transfer roller 12 and the like shown in FIG. To do.

  Further, the printer printing unit 38 controls the drive output to the process load such as the applied voltage of the image forming unit having the driven unit such as the initialization charging roller and the optical writing head, and further rotates the transfer belt 3 up and down. The rotation output to be moved and the drive output of the rotation drive of the transfer belt 3 are controlled.

  The image forming data for each color toner of the decoloring toner R (or black toner K), magenta toner M, cyan toner C, and yellow toner Y output from the PR_CONT 37 is output from the printer printing unit 38, respectively. The corresponding image forming unit 6 shown in FIG. 1 is supplied to an optical writing head (not shown in FIG. 1).

  Further, the decoloring / gloss providing unit 45 determines whether the processing mode instructed by the user or the host device is a decoloring mode for a decolorable toner image or a glossing mode for a toner printed image. The drive control for the applying device 24 is switched.

  That is, in the erasing mode of the erasable toner image, the erasing heat source 27 of the erasing unit 26 is driven to generate heat and the erasing light source 28 of the erasing unit 26 is driven to irradiate. The color erasable toner image of the recording medium 15 on which the color erasable toner image conveyed by the color / gloss imparting device 24 is printed is erased.

  When the print mode is designated here, the decolored recording medium 15 is conveyed along the conveyance path with the arrows c and b as described above, and further, according to the designation of either a color image or a single color image. Thus, the new toner image of the above-described color image or single color image is transferred while passing through the secondary transfer portion.

  On the other hand, in the glossing mode, the color erasing heat source 27 of the color erasing unit 26 is driven to generate heat, and the irradiation driving of the color erasing light source 28 of the color erasing unit 26 is prohibited, thereby erasing and glossing. Only the heat of the color erasing heat source 27 is applied to the toner image of the recording medium 14 or 15 on which the toner image has been printed conveyed by the applying device 24.

  In this gloss application mode, the toner image on the recording medium 14 or 15 on which the toner image has been printed is a monochrome or color image using ordinary toner, and a printed image such as a photograph is particularly effective.

  This is because, if a character image is glossy, the glossiness is obstructive and it becomes difficult to read the character, so generally a glossy character image is not preferred.

  In this example, in the glossing mode, the recording medium 14 or 15 on which a monochrome or color photographic image is printed with normal toner is accommodated in the lower paper feed cassette 23 in advance.

  In the glossing mode, blank paper printing is set. In blank paper printing, the transfer belt 3 is separated from the photosensitive drums 7 of the four image forming units 6, and no toner image is transferred to the transfer belt 3. Further, the fixing unit 18 is not driven by heat and is merely rotationally conveyed.

  Therefore, the print medium 14 or 15 only passes through the secondary transfer unit and the fixing unit 18 after being given only the heat of the decoloring heat source 27 by the decoloring / gloss applying device 24, and is discharged as it is. It is discharged onto the tray 22.

  In this way, the toner image of the recording medium 14 or 15 on which the toner image has been printed is passed through the decoloring / gloss imparting device 24 that is driven to generate heat by the decoloring heat source 27, whereby the toner of the toner image on the surface of the printed material is removed. When the toner image is melted and the surface tension of the toner resin becomes smooth, the toner image becomes smooth and the glossiness is improved.

  The inventor measured the glossiness of the toner image of the recording medium 14 or 15 on which the toner image has been printed by heating the decoloring heat source 27 with heat generation, using a gloss meter. A PG-1 type manufactured by Nippon Denshoku Industries Co., Ltd. was used for the gloss meter.

  As a measurement method, a value measured at an irradiation angle of 75 degrees according to JIS Z 8741 was used. As the toner image, a solid image printed by a printer SPEDIA N3600 manufactured by CASIO was used as a measurement target.

  In addition, according to the measurement experience to date, the gloss level after printing is about 15 to 20 in the printed matter using the mat type toner, and the gloss level after printing when the gloss type toner is used is about It was in the range of 30-50.

  In the above measurement results, the recording medium 14 or 15 on which the toner image has been printed and whose glossiness after printing is in the range of 15 to 30 regardless of whether the toner is mat-based toner or gloss-based toner is used as a heat source for erasing. The glossiness after the 27 was driven to generate heat and passed through the decoloring / gloss imparting device 24 increased to around 40 in all cases.

  As described above, according to the first embodiment of the present invention, a decoloring / gloss imparting device is used by erasing a erasing (decolorizing) printed erasable toner image. By using the erasing unit as it is, it is possible to give gloss to the surface of the toner image on which printing has been completed without changing the fixing device and other configurations.

  FIG. 3 is a cross-sectional view schematically showing only an essential part of the internal configuration of the image forming apparatus with a decoloring and glossing device according to the second embodiment. In FIG. 3, the same components as those in FIG. 1 are denoted by the same reference numerals as in FIG.

  As shown in FIG. 3, the decoloring / gloss imparting device 47 in the image forming apparatus with the decoloring / gloss imparting device of this example is the same as the ceramic heater 48 as a heat source and the decoloring light source shown in FIG. Two erasing units 49 each including the erasing light source 28 are provided. The two erasing units 49 are arranged in a point-symmetrical position with respect to the paper transport unit 25.

  FIGS. 4A and 4B are diagrams for explaining the decoloring efficiency and the heating efficiency by disposing the decoloring unit 49 in a point-symmetrical position with respect to the paper transport path 25 as shown in FIG.

  As shown in FIG. 4A, if the erasing unit 47 is point-symmetric with respect to the paper transport path 25, that is, the recording medium 14 or 15, it must be disposed obliquely with respect to the paper transport path 25. A non-uniform portion of heat radiated from the ceramic heater 48 is also a point object.

  For example, when the upper portion is a portion 51 having a large thermal energy, the lower portion is a portion 52 having a small thermal energy, and when the lower portion is a portion 53 having a large thermal energy, the upper portion is a portion 54 having a small thermal energy. Therefore, it can be seen that the entire structure is uniformized.

  The diagram shown in FIG. 4 (a) shows the operation when the erasable toner images on both sides are erased at that time. As indicated by the arrows, the ceramic heater 48 is driven to generate heat and the eraser is erased. The LED 32 of the color light source 28 is driven to emit light.

  The diagram shown in FIG. 4B shows the operation when a gloss is applied to a printed toner image. As indicated by the arrow, only the ceramic heater 48 is driven to generate heat, and the LED 32 of the decoloring light source 28 is driven. Is prohibited from emitting light and is not irradiated with unnecessary decoloring light.

  In order to give gloss to a printed toner image, for example, the paper conveyance path 25 is formed into a rough wire net shape, the recording medium 14 or 15 on which the toner image is printed is conveyed, and the thermal radiation of the ceramic heater 48 is irradiated from above and below. .

  As described above, since the thermal energy applied to the recording medium 14 or 15 is uniform as a whole, the toner image printed on the recording medium 14 or 15 can be given gloss without any spots.

  The present invention is capable of printing a color image and a color erasable toner image, erasing the color erasable toner image, and forming an image with a color erasing / gloss imparting device capable of imparting gloss to an image with a normal toner. Can be used in the device.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus with decoloring and gloss imparting apparatus 2 Main body case 3 Transfer belt 4 Drive roller 5 Driven roller 6 (6r (6k), 6y, 6c, 6m) Image forming unit 7 Photosensitive drum 8 Developing roller 9 Toner Container 12 Secondary transfer roller 14, 15 Recording medium 16 Upper sheet feeding cassette 17 Fixing conveyance path 18 Fixing section 19 Heating roller 21 Pressing roller 22 Paper discharge tray 23 Lower sheet feeding cassette 24 Decoloring and gloss imparting device 25 Paper conveyance path 26 Decoloring unit 27 Decoloring heat source 28 Decoloring light source 29 Reflector 31 Halogen lamp 32 LED
33 LED holding part 34 (34a, 34b) Conveying roller pair 35 CPU (central processing unit)
36 Interface Controller (I / F_CONT)
37 Printer Controller (PR_CONT)
38 Printer printing section 41 ROM (read only memory)
42 EEPROM (electrically erasable programmable ROM)
43 Operation Panel 44 Sensor 45 Decoloring / Glossing Unit 46 Frame Memory 47 Decoloring / Glossing Device 48 Ceramic Heater 49 Decoloring Unit 51, 53 Large Thermal Energy 52, 54 Small Thermal Energy

Claims (2)

Mode switching means for switching between a color image print mode, a monochromatic toner print mode, a decolorable toner image decoloring mode, and a glossing mode for toner printed images;
Full-color image printing means for driving a magenta, cyan, yellow toner image forming unit or further a black toner image forming unit to print a full color image on a recording medium when the color image printing mode is switched. When,
When the printing mode is switched to the monochrome toner printing mode, the black toner image forming unit or the image forming unit of the erasable toner mounted in exchange for the black toner image forming unit is driven to black the recording medium. Monochrome image printing means for printing a monochrome image with toner or decolorizable toner;
When the color erasing mode is switched to the color erasing mode, the color erasing heat source of the color erasing unit is driven to generate heat and the color erasing light source of the color erasing unit is radiated and driven. An erasable toner image erasing means for erasing the erasable toner image of a printed recording medium;
Toner image printing that is transported through the erasing part by switching the erasing heat source of the erasing unit to generate heat and prohibiting the irradiation of the erasing light source of the erasing unit when switched to the glossing mode Toner image gloss imparting means for imparting gloss to the toner image of a finished recording medium;
An image forming apparatus with a decoloring / gloss imparting device.   2. The image forming apparatus with a decoloring / gloss imparting device according to claim 1, wherein the decoloring heat source of the decoloring unit is a halogen light heater, a carbon heater, or a ceramic heater.