JP2013003483A - Glossiness imparting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress generation of uneven glossiness in a glossiness imparting device.SOLUTION: A glossiness imparting device 100 comprises: a glossiness imparting heating roller 21 which is heated by a heat source and rotates; an endless belt 24 rotating by being stretched by a plurality of rollers including the glossiness imparting heating roller 21; a glossiness imparting pressure roller 22 which is brought into pressure contact with the glossiness imparting heating roller 21 via the endless belt 24 to form a nip portion; and cooling means 28 for cooling the endless belt 24. In the glossiness imparting device 100, a recording material P formed with a toner image thereon is made to advance into the nip portion, the recording material P is conveyed in a state of the recording material P brought into contact with the endless belt 24 from the nip portion and the recording material P is peeled from the endless belt 24 after being cooled by the cooling means 28. The glossiness imparting device 100 further includes removal means 40 for removing foreign matter on the toner image on a nip portion upstream side in a conveyance path of the recording material P.

Description

  The present invention relates to a gloss applying device. More specifically, the present invention relates to a gloss applying device for a toner image on which an image is formed and fixed by an image forming apparatus using an electrophotographic system such as a copying machine, a printer, a facsimile machine, or a combination of these.

  When an electrophotographic image forming apparatus obtains a toner image using a toner made of a heat-meltable resin or the like, an unfixed toner image transferred to a recording material (also referred to as recording paper, paper, or recording medium) In order to fix the toner, a fixing device for heating and pressing is provided.

  FIG. 7 is a schematic configuration diagram of a conventional general two-roller type fixing device. In this fixing device, a nip portion is formed by a heating roller 301 and a pressure roller 303 each having a heat source 302 disposed therein. The heating roller 301 is rotationally driven in the clockwise direction, and the pressure roller 303 rotates with the heating roller 301. The surface of the heating roller 301 is heated by the heat of the heat source 302 and is held at a temperature higher than the temperature at which the toner is softened.

  The recording material on which the unfixed toner image is transferred is sent to a nip portion between the heating roller 301 and the pressure roller 303, and heat and pressure are applied from the heating roller 301 and the pressure roller 303 to the nip portion. As a result, the toner of the unfixed toner image is softened or melted, and after being removed from the nip, is cooled and fixed to the surface of the recording material. However, the toner image obtained by the fixing device having such a configuration has a problem that the glossiness of the image is not sufficient.

  In order to solve the above problems, the present invention relates to a gloss imparting means (gloss imparting device) which imparts a suitable gloss to a high image quality when a toner image formed on a recording material is fixed by a fixing device or after fixing by a fixing device. A number of techniques have been proposed.

  For example, Patent Document 1 discloses a method in which a recording paper is cooled by a cooling means in a state where the recording paper is in contact with an endless belt, and the viscosity of the thermoplastic resin of the recording paper is higher than the viscosity of the color toner. A color image forming apparatus is disclosed in which the temperature in the fixing nip is set so that the elasticity of the thermoplastic resin of the recording paper is smaller than that of the color toner.

  Patent Document 2 discloses a method in which a recording paper is cooled by a cooling structure in a state where the recording paper is in contact with an endless belt, and then peeled off. The endless belt is in contact with the pressure cooling surface of the cooling structure. There is disclosed a fixing device in which a cooling structure is disposed so that a bending angle of a portion that is bent until it leaves is within a predetermined angle range.

  Further, Patent Document 3 discloses a method in which a recording sheet is cooled by a cooling unit in contact with an endless belt and then peeled, and the peripheral speed of the peeling roll (second driving roll) is set to a fixing roll. A belt fixing device that is set to be faster than the peripheral speed of the (first drive roll) is disclosed.

  In the belt-type gloss imparting device as disclosed in the above-mentioned patent document, the toner is once melted in the nip portion formed by the fixing roller on which the endless belt is stretched and the pressure roller, and the toner and the endless belt The toner and the endless belt are brought into close contact with each other by the close contact force, and are conveyed in a close contact state. Further, after being cooled in the conveyance process, the toner and the endless belt are peeled off. Thereby, the surface state of the endless belt is transferred to the surface of the toner, the surface of the toner is smoothed, and the glossiness of the toner image can be increased.

  Therefore, in order to obtain a high gloss image, the surface property of the endless belt and the adhesion between the toner and the endless belt are important.

  However, since the recording material conveyed through the image forming apparatus is passed through the gloss applying device, the recording material falls on the toner image of the recording material from the paper dust / dust / fixing device member. In some cases, the toner is transported in a state where foreign matter such as a lump of toner is attached.

  As described above, when foreign matter adheres to the toner image, the adhered portion of the foreign matter and the peripheral portion thereof do not adhere to the endless belt, so that the glossiness does not increase only in that portion and gloss unevenness may occur. Has occurred.

  Therefore, the present invention removes the foreign matter on the toner image by the removing means and then transports the toner image on the recording material to the nip portion without any foreign matter, thereby bringing the toner and the endless belt into intimate contact with each other. An object of the present invention is to provide a gloss applying device that suppresses occurrence of uneven gloss.

  In order to achieve such an object, a gloss imparting device according to the present invention includes a heating roller that is heated and rotated by a heat source, an endless belt that is stretched around a plurality of rollers including the heating roller, and an endless belt. A pressure roller that presses against the heating roller via the belt to form a nip portion, and a cooling means that cools the endless belt, and the recording material on which the toner image is formed enters the nip portion, In a gloss applicator that is transported in contact with an endless belt from the nip portion and then peeled off from the endless belt after being cooled by the cooling means, foreign matter on the toner image is located upstream of the nip portion in the recording material transport path. It has the removal means which removes.

  According to the present invention, it is possible to eliminate the occurrence of uneven glossiness by transporting the toner image to the nip portion without any foreign matter and bringing the toner and the belt into close contact with each other.

It is a basic lineblock diagram of a gloss grant device. It is a schematic block diagram of the glossiness imparting device concerning this embodiment, and is an example which has a fan as a removal means. It is a schematic block diagram of the gloss provision apparatus which concerns on this embodiment, Comprising: It is an example in which a fan utilizes exhaust air. FIG. 4 is a top view of the gloss applying device shown in FIG. 3. FIG. 3 is a schematic configuration diagram illustrating a connection state between an image forming apparatus main body and a gloss imparting apparatus main body. It is a schematic block diagram of the gloss provision apparatus which concerns on other embodiment, Comprising: It is an example which has a brush as a removal means. It is a schematic block diagram of the fixing device by the conventional 2 roller system.

  Hereinafter, a configuration according to the present invention will be described in detail based on the embodiment shown in FIGS.

(Basic configuration of gloss applicator)
The gloss imparting device can obtain a high glossiness such as a photographic image by passing the recording material on which the toner image is fixed by the electrophotographic image forming apparatus through the gloss imparting device. .

  First, the basic configuration of the gloss applying device will be described with reference to FIG. A gloss applying device 100 shown in FIG. 1 is a belt-type gloss applying device in which an endless belt 24 is stretched around three rollers: a gloss applying heating roller 21, a support roller 26, and a peeling roller 27.

  In the gloss imparting device 100, the recording material P on which the toner image T has been fixed after passing through the image forming device has a nip formed by the gloss imparting heating roller 21 and the gloss imparting pressure roller 22 of the gloss imparting device 100. Passed and heated. After passing through the nip portion, the recording material P is conveyed while being in close contact with the surface of the endless belt 24, and is peeled off at the peeling roller 27.

  Further, while the recording material P is in close contact with the endless belt 24, the recording material P is cooled together with the endless belt 24 by a cooling device 28 provided in the endless belt 24 and a cooling fan 29 installed below the belt. The toner image T is peeled off in a solidified state by being cooled below the glass transition temperature of the toner. As a result, the glossiness of the toner image T can be increased.

  A gloss imparting pressure roller 22 is in pressure contact with the gloss imparting heating roller 21 via an endless belt 24. Further, the gloss imparting heating roller 21 is provided with a halogen heater 23 as a heating source. Further, a thermistor 25 is provided as temperature detecting means for detecting the temperature of the surface of the endless belt 24, and the halogen heater 23 is turned on / off by a control device (not shown) based on the temperature detection result by the thermistor 25. The temperature of the endless belt 24 is controlled.

  A cooling device 28 is provided on the inner peripheral side of the endless belt 24. The cooling device 28 cools the endless belt 24 on the downstream side in the sheet passing direction of the recording material P in the nip portion formed by the press-contact of the gloss imparting heating roller 21 and the gloss imparting pressure roller 22. The recording material P conveyed in close contact with the surface of the belt 24 is cooled.

  As the cooling device 28, for example, a heat sink as shown in FIG. 1 is brought into contact with the inner peripheral side of the endless belt 24, and air is blown to the heat sink by a cooling fan (not shown in FIG. 1). Can be used. The configuration of the cooling device 28 is not particularly limited. For example, a cooling fan is installed on the inner peripheral side of the endless belt 24, and the endless belt 24 is directly cooled by air from the cooling fan. Alternatively, a Peltier cooling mechanism for cooling the endless belt 24 may be provided by using a semiconductor element (Peltier element) utilizing the Peltier effect.

  Further, a cooling fan 29 for cooling the surface of the endless belt 24 from the lower side of the surface of the endless belt 24 and the recording material P from the back side is installed, and the endless belt 24 and the recording material P are both vertically positioned. By cooling from the direction, it is possible to cool quickly.

  Further, an inlet guide member 30 and an outlet guide member 31 for guiding the conveyance of the recording material P are provided on the entry side to the nip portion and on the downstream side of the peeling roller 27, respectively. The above is the basic configuration of the gloss applying device 100.

(First embodiment)
[Constitution]
The configuration of the gloss imparting apparatus 100 according to the present embodiment will be described with reference to FIG. The gloss imparting device 100 according to the present embodiment includes a heating roller (gloss imparting heating roller 21) that is heated and rotated by a heat source (halogen heater 23), and a plurality of rollers including a heating roller (a support roller 26 and a peeling roller 27). An endless belt (endless belt 24) that is stretched around and rotated, and a pressure roller (gloss imparting pressure roller 22) that presses against the heating roller via the endless belt to form a nip portion; A cooling means (cooling device 28, cooling fan 29) for cooling the endless belt, and a recording material (recording material P) on which a toner image (toner image T) is formed enters the nip portion, and the nip In a gloss imparting device (gloss imparting device 100) that is transported in a state where it is in contact with the endless belt from the head, cooled by the cooling means, and peeled off from the endless belt (gloss imparting device 100), The nip portion upstream of, and has a removal means for removing foreign matter on the toner image (removing means 40).

  In the gloss imparting apparatus 100 described in FIG. 1, the recording material P on which the toner image T is fixed after passing through the image forming apparatus is fed. In some cases, foreign matter such as powder or lump of toner dropped from a roller or the like in the image forming apparatus may adhere. Even if the size of the foreign matter is very fine, such as several micrometers, for example, the toner and the endless belt 24 are not completely in contact with each other on the foreign matter attached portion and its peripheral portion. In that portion, sufficient gloss cannot be obtained, resulting in a problem of uneven gloss.

  Therefore, in addition to the configuration shown in FIG. 1, the gloss imparting apparatus 100 shown in FIG. 2 has a recording material P that enters a nip portion formed by press-contacting the gloss imparting heating roller 21 and the gloss imparting pressure roller 22. It is provided with a removing means 40 for removing foreign matters such as paper dust, dust on the recording material P, and toner lumps dropped from a member in the fixing device immediately before printing (immediately before the upstream side in the sheet passing direction).

  In the gloss imparting apparatus 100 shown in FIG. 2, the removing means 40 is constituted by an intake fan 41, a duct 42 and an exhaust fan 43. Air is blown out by an intake fan 41 installed at the top, passes through the duct 42, and blows air onto the recording material P immediately before the nip portion.

  Further, it is preferable that an exhaust fan 43 is provided on the upstream side in the sheet passing direction, and the air blown to the recording material P is sucked and exhausted so as not to go to the nip portion direction. Further, the air outlet side of the duct 42 is bent in a direction opposite to the nip portion so that air flows in a direction opposite to the nip portion.

  2 shows a cross-sectional configuration of the gloss imparting apparatus 100, the removal means 40 is formed over substantially the entire width direction of the recording material P (which is a direction perpendicular to the paper passing direction). It is preferred that

  By configuring the removing means 40 as described above, foreign matters such as dust attached on the toner image before the recording material P enters the nip portion can be removed. Further, foreign matter such as removed dust is exhausted so as not to go to the nip portion side by the air flow, so that it can be prevented from being reattached on the toner image.

  Here, the intake fan 41 may suck air outside the apparatus to generate an air flow, but the air blown from the intake fan 41 is air heated to a temperature higher than room temperature. It is preferable.

  As described above, when heated air is used as the air to be blown onto the recording material P, the recording material P once heated by the image forming apparatus can enter the nip portion of the gloss imparting device 100 without cooling. In addition, the power for heating in the gloss applying device 100 (the amount of power supplied to the halogen heater 23) can be reduced, and the power consumption can be reduced.

  Here, in order to use the air heated to a temperature higher than the room temperature, a heating means for heating the air may be provided separately. However, like the gloss imparting device 100 shown in FIG. As the heated air, the heated air used for cooling the endless belt 24 of the gloss imparting device 100, specifically, the cooling device 28 used for cooling the endless belt 24 is cooled. It is preferable to circulate and reuse the air for generating the air.

  FIG. 4 shows a top view of the gloss applying device 100 shown in FIG. 3, and air circulation will be described with reference to FIG. In the gloss imparting device 100 shown in FIG. 3, as shown in FIG. 4, in order to cool the heat sink as the cooling device 28 provided on the inner peripheral side of the endless belt 24, air is supplied to the heat sink by the intake fans 45a and 45b. This is exhausted and sucked up by the exhaust fans 46 a and 46 b, and this exhaust hot air is sent to the intake fan 41 through the duct 44 and blown to the recording material P through the duct 42.

  As described above, by using the heated exhaust air used for cooling the cooling device 28, a heating unit for heating the air becomes unnecessary, so that power consumption is reduced and space is saved. be able to.

  Next, the connection between the gloss applying apparatus main body 101 in which the gloss applying apparatus 100 is housed in the housing and the image forming apparatus main body 200 will be described with reference to FIG.

  FIG. 5 is a schematic diagram showing a state in which the gloss providing apparatus main body 101 is connected to the image forming apparatus main body 200. In FIG. 5, the recording material P on which image formation and fixing has been performed by the image forming apparatus main body 200 is discharged from the image forming apparatus main body 200, and recording is performed on the gloss imparting apparatus main body 101. A paper feed port (paper feed unit) 102 for the material P is connected. In other words, the conveyance path of the recording material P of the image forming apparatus main body 200 is directly connected to the gloss applying device 100, and the recording material P on which image formation and fixing have been performed by the image forming device main body 200 is provided with a single pass. be able to.

  As described above, since the image forming apparatus main body 200 and the gloss imparting apparatus main body 101 can be connected and used, it is not necessary to take out the recording material P and the recording material P is not exposed to the atmosphere. It is possible to reduce contamination and adhesion of foreign matters such as dust.

[Operation example]
An example of the operation of the gloss applying device 100 described above will be described. First, the recording material P printed by the image forming apparatus main body 200 and fixed by the fixing device included in the image forming apparatus is conveyed to the gloss applying apparatus main body 100 as it is, and the gloss applying heating roller 21 and the gloss applying pressure roller 22 are transferred. The toner enters the nip portion formed by the above process and is heated, so that the toner is in a molten state. At this time, the set temperature of the endless belt 24 is 150 ° C., for example.

  In this state, the recording material P is conveyed while being in close contact with the endless belt 24. The distance from the nip portion of the gloss imparting device 100 to the peeling point (peeling roller 27) is, for example, 120 mm. During this 120 mm, cooling is performed by the cooling device 28 and the cooling fan 29, and at the position of the peeling roller 27. And cooled to about 40 ° C.

  After cooling, the toner is peeled off from the endless belt 24, whereby the toner is peeled off in a cooled and solidified state, and a high gloss image having a glossiness of about 80% can be obtained. However, in order to obtain such a high gloss level, it is necessary that the toner on the recording material P and the endless belt 24 are completely in close contact as described above.

  Therefore, as described above, the gloss imparting device 100 includes the removing unit 40 and removes foreign matter by blowing air onto the toner image T of the recording material P immediately before the nip portion. Here, the surface temperature of the recording material P when the recording material P is discharged from the image forming apparatus main body 200 and enters the gloss applying apparatus main body 101 is about 70 ° C.

  Here, for example, when air at room temperature is used for blowing air, when entering the nip portion of the gloss imparting device 200, the air enters the nip portion at a temperature lowered to about 50 ° C. In order to raise temperature, the power consumption for heating the gloss imparting heating roller 21 increases.

  On the other hand, by using the exhausted hot air used for the cooling process of the endless belt 24 as the air blown to the recording material P (see FIGS. 3 and 4), the recording material P enters the nip portion without lowering the temperature. Therefore, the power consumption for heating the gloss imparting heating roller 21 can be reduced.

  The gloss imparting apparatus according to the present embodiment described above is provided with an air flow by a fan as a means for removing foreign matter on the toner image, and the air flow is an air flow that does not go toward the nip portion. Can be prevented from re-adhering to the nip, and the toner can be transported to the nip without any foreign matter on the toner image, and the toner and belt can be brought into close contact with each other, thereby suppressing gloss unevenness. Can do.

(Second Embodiment)
In the first embodiment, the example in which the removing unit 40 is configured by a fan has been described. However, the removing unit 40 may be configured by a brush 47 as illustrated in FIG. 6.

  In the second embodiment, the recording material immediately before the recording material P enters the nip portion formed by press-contacting the glossing heating roller 21 and the glossing pressure roller 22 (immediately before the upstream side in the sheet passing direction). As the removing means 40 for removing the foreign matter on P, a roller-like brush 47 is installed so as to be able to rotate counterclockwise (counterclockwise) from the paper direction. The brush 47 is rotationally driven by a driving unit (not shown) connected to the brush 47.

  According to the example shown in FIG. 6, the foreign matter on the toner image T can be removed by rotating the tip of the brush 47 in contact with the recording material P being conveyed. Further, the rotation direction of the brush 47 may be a direction opposite to the paper passing direction (counterclockwise) or a direction rotating in the paper passing direction (clockwise).

  The gloss imparting apparatus according to the second embodiment described above can scrape foreign matter on the toner image by rotating a brush formed as a roller as means for removing foreign matter on the toner image. The toner is conveyed to the nip portion without any foreign matter on the image, and the toner and the belt can be brought into close contact with each other, so that occurrence of uneven gloss can be suppressed.

  The above-described embodiment is a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the gist of the present invention.

  For example, in the first and second embodiments described above, the removal means 40 has been described with respect to the configuration of the fan (the intake fan 41, the duct 42, the exhaust fan 43) and the configuration of the brush (the brush 47). It is also preferable to provide both removing means 40 in the conveyance path in juxtaposition in the sheet passing direction. For example, by providing a fan on the upstream side in the paper direction and a brush on the downstream side, even if there is foreign matter that cannot be removed by the fan, it can be removed by the brush and more effectively on the recording material P. Foreign matter can be removed. Of course, the arrangement order may be reversed.

21 Gloss imparting heating roller 22 Gloss imparting pressure roller 23 Halogen heater 24 Endless belt 25 Thermistor 26 Support roller 27 Peeling roller 28 Cooling device 29 Cooling fan 30 Inlet guide member 31 Outlet guide member 40 Removing means 41 Intake fan 42 Duct 43 Exhaust Fan 44 Duct 45a, b Intake fan (for cooling device)
46a, b Exhaust fan (for cooling device)
47 Brush 100 Gloss imparting device 101 Gloss imparting device main body 102 Paper feed port 200 Image forming device main body 201 Paper discharge port P Recording material T Toner image

JP 2002-91048 A JP 2002-99168 A JP 2003-270987 A

Claims (9)

A heating roller that is heated and rotated by a heat source;
An endless belt that is stretched around and rotated by a plurality of rollers including the heating roller;
A pressure roller that presses against the heating roller via the endless belt to form a nip portion;
Cooling means for cooling the endless belt,
Gloss imparting that allows a recording material on which a toner image is formed to enter the nip portion, is conveyed in contact with the endless belt from the nip portion, is cooled by the cooling means, and then peels off from the endless belt. In the device
A gloss applying apparatus, comprising: a removing unit that removes foreign matter on the toner image on the upstream side of the nip portion in the conveyance path of the recording material.   The gloss applying apparatus according to claim 1, wherein the removing unit is a fan.   The gloss applying apparatus according to claim 2, wherein the removing unit removes foreign matter on the toner image by generating an air flow in a direction different from the nip portion direction.   The gloss applying apparatus according to claim 2 or 3, wherein the air from the removing means is air heated to a temperature higher than room temperature.   The gloss applying device according to any one of claims 2 to 4, wherein the air from the removing means is heated air used for cooling the endless belt.   The gloss applying apparatus according to claim 1, wherein the removing unit is a brush.   The gloss imparting apparatus according to claim 6, wherein the brush is formed in a roller shape, and foreign matter on the toner image is removed by rotating a tip portion of the brush in contact with the recording material.   The gloss applying apparatus according to claim 1, further comprising a fan and a brush as the removing unit.   9. The gloss applicator according to claim 1, wherein the recording material feeding unit to the gloss applicator is connectable to a paper discharge unit of the image forming apparatus.