JP2007304308A - Fixing device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fixing device in which energy saving can be achieved in a step for fixing a latent image to a recording medium and which is provided with stable fixing performance and rapid fixing time in combination, and an image forming apparatus. <P>SOLUTION: The fixing device includes a fixer imparting means for imparting a fixer containing a softener having the property to soften resin particulates to an unfixed image formed by the resin particulates on a recording medium, and a fixer impartation amount adjusting means for adjusting the imparting amount by the fixer imparting means, and therefore, if the impartation amount of the fixer fluctuates, the impartation amount can be adjusted, and the fixing device provided with the stable fixing performance and the rapid fixing time in combination can be provided. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fixing device and an image forming apparatus, and more particularly to an image fixing device using an electrophotographic system such as a copying machine, a printer, a facsimile machine, or the like.

  2. Description of the Related Art Image forming apparatuses used for printers, facsimiles, copying machines, and the like are apparatuses that form images such as characters and symbols on recording media such as paper, cloth, and OHP sheets based on image information. There are various types of such recording apparatuses, and in particular, an electrophotographic image forming apparatus is widely used in offices because it can record high-definition images on plain paper at high speed. In such an electrophotographic image forming apparatus, the toner on the recording medium is heated and melted from the viewpoint of fixing speed, fixed image quality, etc., and the melted toner is pressed to apply the toner onto the recording medium. The heat fixing method for fixing to the surface is widely spread.

  However, about half or more of the power consumption in these image forming apparatuses is consumed for heat fixing type toner heating, and a low power consumption (energy saving) fixing device is desired from the viewpoint of reducing environmental load in recent years. Yes. In other words, fixing is desired in which the heating temperature at the time of fixing is extremely lower than before or heating is not required. From the viewpoint of energy saving, it is ideal to fix the toner without heating at all. As this non-heat fixing method, so-called solvent fixing in which a solvent that dissolves the toner resin is applied to the unfixed toner is known.

  As a conventional example of this non-heat fixing method, in Patent Document 1, Patent Document 2 and Patent Document 3, a fixing solution for dissolving or swelling the toner is applied to the toner to dissolve or swell the toner. A method for fixing toner by drying has been proposed. This non-heat fixing method does not require a heat treatment for dissolving the toner as in the case of the heat fixing method, and thus can be said to be an excellent fixing method with low power consumption and energy saving measures.

  However, in the above prior art, water, which is a dispersion medium of the softener, does not correspond to VOC (volatile organic compound) and there is no problem. However, for other organic compounds in the softener, odor (unpleasant odor or irritating odor) ) And safety (PRTR law varieties and Proposition 65 varieties) are listed as examples in the examples, etc. When used in the office environment, the materials that are harmful to the human body and uncomfortable Odor fills the office and its use in the office environment is a problem. In addition, when a large amount of fixing agent is applied to an unfixed toner image, wrinkles and curls occur on the recording medium due to moisture absorption, and the stable and high-speed recording medium (transfer paper) conveyance necessary for the image forming apparatus is significantly impaired. It will be. Further, if this large amount of water is to be removed by evaporation using a drying device, electric power comparable to that of the heat fixing device is required. Further, in order not to impair the fluidity between particles due to the influence of moisture in the atmosphere, the surface of the toner fine particles is treated with water repellency. In the case of a fixing solution using water as a solvent, the fixing solution is applied to an unfixed toner image. At the time of application, there is a serious problem that the toner fine particles are repelled by the fixing liquid and the image is disturbed.

On the other hand, as another solvent fixing method, in Patent Document 4, a toner is dissolved and a solvent having compatibility with silicone oil is mixed with silicone oil to prevent image disturbance due to toner softening. That is, the flow of the softened toner is suppressed by the silicone oil having a relatively high viscosity. Further, the solvent disclosed in Patent Document 4 is an aromatic solvent such as benzene or a ketone solvent such as methyl ethyl ketone, which has volatility and strong odor, and is also problematic from the viewpoint of VOC problem. There are many.
In contrast to these conventional examples, Patent Documents 5 to 8 use a solution that is harmless to the human body as a fixing solution, and further reduces the amount of adhesion on a recording medium such as transfer paper so that wrinkles and curls do not occur. The fixing liquid is applied to the toner before transfer to the recording medium, and a measure is taken to reduce the amount of adhesion on the non-image area.

  However, the method of applying the fixing liquid to the toner before transfer to the recording medium needs to prevent the fixing liquid from being mixed into the toner before the image formation, and it is difficult to handle the liquid. is there.

On the other hand, if a fixer is applied to the image after being transferred onto the recording medium, the fixer is not likely to be mixed into the toner before image formation, and the handling is good. Granted in such a way. In these conventional examples, most of them are applied by contacting a roller holding a fixing solution, but when applied in this way, the toner on the recording medium is transferred to the roller in reverse (offset). ) Occurs. Therefore, an offset is prevented by using an electric field.
Japanese Patent Publication No.49-026591 Japanese Patent No. 3,290,513 JP-A-53-118139 JP 59-119364 A JP 2004-109747 A JP 2004-109749 A JP 2004-109750 A JP 2004-109751 A

  By the way, there is an appropriate amount of the softening agent applied to the toner particles constituting the image. If the amount is too small, the toner particles cannot be sufficiently softened to be in an incomplete fixing state. It has been found that it takes time for the agent to come off and cure, resulting in a longer fixing time. For this reason, it is desirable to give an amount that is more than the necessary minimum amount and is as close as possible to this amount. For this reason, if the amount of fixing solution applied changes due to changes in the environment such as temperature, problems such as insufficient fixing performance and an increase in the time required to complete fixing occur.

  The present invention is intended to solve this problem, a fixing device and an image that can save energy in the process of fixing a visible image to a recording medium, and have both stable fixing performance and quick fixing time. An object is to provide a forming apparatus.

  In order to solve the above-mentioned problems, the fixing device of the present invention includes a fixing solution containing, as a component, a softening agent having a property of softening resin fine particles with respect to an unfixed image formed by resin fine particles on a recording medium. And a fixing liquid application amount adjusting means for adjusting the amount of the fixing liquid applied by the fixing liquid application means. Therefore, when the amount of fixing liquid applied varies, the amount applied can be adjusted, and a fixing device having both stable fixing performance and quick fixing time can be provided.

  In addition, a temperature detecting means for detecting the temperature of the fixing liquid is provided, and the fixing liquid adjusting means adjusts the application amount of the fixing liquid by the fixing liquid applying means according to the temperature of the fixing liquid detected by the temperature detecting means, It is possible to predict the fluctuation amount by detecting the temperature that causes the fluctuation of the applied amount.

  Further, the temperature detection means can accurately measure the temperature required for predicting the fluctuation of the fixing liquid application amount by detecting the surface temperature of the fixing liquid application means.

  Further, the temperature detecting means can accurately measure the temperature required for predicting the fluctuation of the fixing liquid application amount by detecting the surface temperature of the fixing liquid application amount adjusting means.

  Further, since the temperature detecting means is a non-contact temperature detecting means, the temperature can be measured without damaging the supply member.

  Further, since the cooling means for cooling the fixing liquid applying means is provided, the influence of the temperature rise due to the operation of the apparatus can be reduced. This cooling means is preferably a forced air cooling mechanism or a liquid cooling mechanism.

  Further, an image forming apparatus as another invention is characterized by including the above-described fixing device. Accordingly, since heat energy is not used for fixing, not only the power used during operation can be greatly reduced, but also there is no need to preheat like a heat roller, so that it is possible to provide an image forming apparatus that can reduce power during standby. it can.

  According to the fixing device of the present invention, when the amount of fixing liquid applied is changed by the fixing liquid application amount adjusting unit that adjusts the amount of fixing liquid applied by the fixing liquid applying unit, the application amount can be adjusted stably. A fixing device having both fixing performance and quick fixing time can be provided.

  FIG. 1 is a schematic configuration diagram showing a configuration of an image forming apparatus according to an embodiment of the present invention. A copying machine, which is an image forming apparatus according to the present embodiment, includes a charger 12, an exposure device 13, a developing device 14, a transfer device 15, a static elimination lamp 16, and a cleaning device around a photosensitive member 11 as a latent image carrier. 17 is disposed. As the material of the photoconductor 11, amorphous silicon (a-Si), organic photoconductor (OPC), or the like can be used. Further, as the charger 12, a form such as a roller or a charger can be used. Further, as the exposure device 13, an LED, a laser scanning optical system, or the like can be used.

  A case where an image is formed by reversal development with the copying machine having such a configuration will be described. The photoconductor 11 is rotationally driven in the direction of the arrow at a constant speed during copying by a driving means such as a motor (not shown). Then, after being uniformly charged in the dark by the charger 12, the original light image is irradiated and formed by exposure from the exposure device 13, and the electrostatic latent image is carried on the outer peripheral surface of the photoconductor 11. . Thereafter, the electrostatic latent image is developed while passing through a portion of the developing device 14. The toner image developed into the electrostatic latent image is transferred to the intermediate transfer roller 15-1 by the transfer device 15 and then transferred to the transfer paper 18. After the transfer, the residual potential of the photoconductor 11 is removed by the charge eliminating lamp 16, and the residual toner is removed by the cleaning device 17 to prepare for the next image formation. Then, the transferred transfer paper 18 is conveyed to the fixing device 19 of the present invention. Next, an electric field that presses the toner particles against the transfer paper 18 is formed by the electric field applying means of the transfer device 19, and then a fixing liquid containing a component that dissolves the resin particles of the toner by the fixing liquid applying means. To fix the toner particles in a dissolved and swollen state. At this time, since the bonding property between the transfer paper 18 and the toner particles is enhanced by the electric field applying means in advance, the toner particles can be prevented from flowing due to the application of the fixing liquid, so that the image disturbance can be prevented.

  The developer used in the copying machine, which is the image forming apparatus of the present embodiment, has a low viscosity (about 1 cSt) and low concentration (1 cSt) using Isopar (Exxon trademark), which is generally commercially available and used conventionally. %)), And a highly viscous and high concentration liquid developer. As the viscosity and concentration range of the developer, for example, a viscosity of 50 to 10,000 mPa · s and a concentration of 5% to 40% are used. As the carrier liquid, a highly insulating material such as silicone oil, normal paraffin, Isopar M (Exxon trademark), vegetable oil, mineral oil or the like is used. Volatile and non-volatile can be selected according to the purpose. The toner that is colored particles mainly consists of a resin such as styrene acrylic, polyester, and epoxy, and a colored pigment that is colored fine particles (such as disazo yellow, quinacridone, copper phthalocyanine, or carbon black), and further has a charge. A control agent and a dispersant may be blended. The average particle size is adjusted to about 3 μm, but it may be selected according to the purpose from submicron to about 6 μm.

Next, the developing device in FIG. 1 will be described.
As shown in FIG. 1, the developing device 14 has a developer encasing tank 14-1, a developing roller 14-2, a sweep roller 14-3, and a coating means. The application roller 14-4, the intermediate roller 14-5, and the stirring screw 14-6 are mainly configured. The sweep roller 14-3 and the intermediate roller 14-5 are respectively provided with cleaning members 14-7 and 14-8 made of metal blades or rubber blades. Each cleaning member is not limited to a blade but may be a roller type. The developing roller 14-2 and the sweep roller 14-3 are each provided with an elastic layer having conductivity on the outer peripheral surface. Urethane rubber can be used as the material for these elastic layers. The surface hardness of the elastic layer is preferably 50 degrees or less in terms of JIS-A hardness so that a nip can be efficiently formed with the photoreceptor 11 in FIG. The material of the elastic layer is not limited to urethane rubber, but may be any material that has conductivity and does not swell or dissolve with the carrier liquid / developer. Further, the surfaces of the developing roller 14-2 and the sweep roller 14-3 are electrically conductive and do not swell or dissolve with the carrier liquid / developer, and the carrier liquid / developer contacts the inner layer. If it is the structure which does not carry out, the material of the elastic body layer as the inner layer should just have elasticity, without the restrictions of the said electroconductivity and swelling dissolution. At this time, the development bias voltage and the sweep bias voltage need to be applied from the surface, not from the axes of the development roller 14-2 and the sweep roller 14-3.

  Further, instead of providing the elastic layer on the developing roller 14-2 and the sweep roller 14-3, the elastic layer may be provided on the photosensitive member 11 side. Further, the photoconductor 11 may be constituted by an endless belt-like member. Further, the surfaces of the developing roller 14-2 and the sweep roller 14-3 are configured to have a smoothness of Rz 5 μm or less by coating or a tube.

  When the developing roller 14-2 and the sweep roller 14-3 are brought into contact with the photosensitive member 11 with an appropriate pressure, the elastic layer of each roller is elastically deformed to form a developing nip and a removal nip. To do. In particular, by forming the development nip, it is possible to ensure a certain development time for the toner of the developer to move and adhere to the photoreceptor 11 by the development electric field in the development area. Further, by adjusting the contact pressure, it is possible to adjust the nip width that is the width in the surface movement direction at each nip portion. Each nip width is set to be equal to or greater than the product of the linear velocity of each roller and the development time constant. Here, the development time constant is the time required until the development amount is saturated, and is obtained by dividing the necessary minimum nip width by the process speed. For example, if the required minimum nip width is 5 mm and the process speed is 500 mm / sec, the development time constant is 10 msec.

During the developing operation, a thin layer of developer is formed on the developing roller 14-2 by the application roller 14-4. At this time, the thickness of the developer applied on the developing roller 14-2 was set such that the pigment content in the toner carried per 1 cm ^{2 of the} surface thereof was 3 μg or more and 60 μg or less. For this purpose, a thin layer of developer was applied to a thickness of 3 to 12 μm. The reason for this is that when the developer coating thickness is such that the pigment content in the toner carried per 1 cm ² of the surface of the developing roller 14-2 is less than 3 μg, a sufficient amount of the pigment is exposed to the above photosensitive layer. This is because the image portion of the latent image formed on the body 11 may not move to the image portion and the image density of the image portion may be reduced. In addition, if the pigment content in the toner carried per 1 cm ² of the surface of the developing roller 14-2 is greater than 60 μg, the excess toner remaining on the background after development increases, and the sweep roller 14 This is because the removal by -3 may be incomplete.

  The developer thin layer formed on the surface of the developing roller 14-2 corresponds to the latent image on the photosensitive member 11 when passing through the developing nip formed by the photosensitive member 11 and the developing roller 14-2. Developed. In other words, in the image portion, the toner moves to the photoconductor 11, and in the background portion (non-image portion), the toner moves to the surface of the developing roller 14-2 by an electric field formed by the developing bias potential and the photoconductor potential. To prevent the toner from adhering to the background. However, when a part of the toner on the background portion does not move to the surface of the developing roller 14-2 and remains on the photosensitive member 11, it causes fogging. Therefore, in the developing device 14 of FIG. 1, the above-described sweep roller 14-3 is provided for sweeping (cleaning) toner that causes the fog (hereinafter referred to as fog toner). The sweep roller 14-3 is disposed downstream of the developing roller 14-2 in the rotation direction of the photoconductor 11 and is pressed against the photoconductor 11 so as to sandwich the developed toner layer. The surface of the sweep roller 14-3 removes fog toner from the background while moving at substantially the same speed as the surface of the photoreceptor 11.

  The toner after development by the developing roller 14-2 is removed by a cleaning blade to prevent ghosting, and the liquid developer removed by the sweep roller 14-3 is removed to maintain the sweep performance. These liquid developers are collected in an adjustment tank, and are sent again into the developing unit after the density is adjusted. In the adjustment tank, there are agitation means, concentration detection means (not shown) and liquid amount detection means (not shown), and the concentration and liquid amount are detected in a state where the concentration in the tank is uniform, The density is adjusted by supplying new liquid developer and carrier. The amount of liquid developer applied to the developing unit from here is set to be slightly larger than the amount of liquid developer used, and the overflow amount returns to the adjustment tank. It always comes to circulate.

Next, the fixing device of the present invention will be described.
FIG. 2 is a schematic sectional view showing the structure of the fixing device according to the embodiment of the present invention. In the figure, the same reference numerals as those in FIG. 1 denote the same components. The fixing device 19 according to the present embodiment shown in the figure includes a fixing roller 19-1, which is a fixing liquid application unit, a coating roller 19-2, and a transfer paper 18 sandwiched between the fixing roller 19-1. It is mainly comprised from the pressure roller 19-3 which opposes. The application roller 19-2 for supplying a necessary amount of fixing liquid to the fixing roller 19-1 is an anilox roller having a uniform pattern engraved on its surface as shown in FIG. The fixing solution adhering to the fixing roller 19-1 is ground by the doctor blade 19-4, and the amount of the fixing solution is accurately measured by the volume of the groove and supplied to the fixing roller 19-1. Can be supplied to. At this time, the coating roller 19-2 is driven so as to rotate so that the moving direction of the coating roller 19-2 is opposite to the surface moving direction of the fixing roller 19-1, and the surface of the coating roller 19-2 with respect to the fixing roller 19-1 It is possible to easily change the amount of the fixing liquid on the fixing roller 19-1 by adjusting the moving speed.

  Further, the fixing liquid applied on the fixing roller 19-1 is applied by contacting the transfer paper 18 after image transfer at the nip portion with the pressure roller 19-3, and the image is pressed against the transfer paper 18 at this time. By applying such an electric field, the toner on the transfer paper 18 is prevented from being offset to the fixing roller 19-1.

  As described above, the fixing device of this embodiment changes the linear speed of the application roller 19-2 and changes the ratio of the linear speed of the application roller 19-2 to the linear speed of the fixing roller 19-1. It is possible to adjust the application amount of the liquid. In FIG. 3, as an example of the application amount adjusting unit, an example in which an anilox roller is used as the application roller 19-2 and the supply roller 19-1 is supplied to the fixing roller 19-1, but the present invention is not limited thereto. As shown in FIG. 4, an intermediate roller 19-5 may be provided between the anilox roller as the application roller 19-2 and the fixing roller 19-1. In this case, the anilox roller as the application roller 19-2 and the intermediate roller 19-5 are brought into contact with each other at an appropriate pressure so that the intermediate roller 19-5 is caused to follow the application roller 19-2. By making it possible to adjust the rotation speed of 19-5, the supply amount of the fixing liquid can be adjusted. In this configuration, the number of rollers is increased as compared with the configuration in FIG. 3, but since the doctor blade 19-4 is not used, it is possible to prevent problems due to contamination of the blade tip.

  FIG. 5 is a characteristic diagram showing the adhesion amount of the fixing liquid on the recording medium when the ratio between the linear speed of the intermediate roller and the linear speed of the fixing roller of the fixing device of this embodiment is changed. In the figure, the amount of adhesion when the roller linear velocity ratio is 1 is 1, and the amount of adhesion is increased or decreased. As can be seen from the figure, the applied amount can be adjusted by changing the roller speed.

  An application amount adjusting means that does not use a roller as shown in FIG. 2 is also possible. For example, when applying a fixing liquid using a nozzle having a configuration like an ink jet printer head, the driving voltage and frequency of a piezo element that generates pressure on the discharge liquid can be adjusted by the head, and the applied amount can be adjusted. It is also possible to adjust.

  By having a mechanism that can adjust the amount of fixer applied in this way, the amount of fixer applied fluctuates due to environmental fluctuations such as temperature. Can be given.

  By the way, as an environmental factor in which the application amount of the fixing liquid fluctuates, the maximum is temperature. Due to the change in temperature, the viscosity of the fixing solution changes, so the amount of the fixing solution passing through the nip portion between the rollers changes, and the applied amount changes. FIG. 6 is a characteristic diagram showing the temperature dependence of the viscosity of the fixing solution. As can be seen from FIG. 6, the viscosity decreases as the temperature increases. FIG. 7 is a characteristic diagram showing a change in the application amount of the fixing liquid with respect to the temperature. The application amount at 25.degree. As can be seen from FIG. 7, when the temperature rises from 25 ° C. to 50 ° C., the applied amount is about 75 to 80%.

  Therefore, it is possible to detect the viscosity of the fixing solution and adjust the applied amount, but in general, the viscometer is complicated and large and is not suitable for incorporation in the apparatus. Therefore, it is conceivable to detect the temperature of the fixing solution and predict the fluctuation of the viscosity of the fixing solution therefrom. For this purpose, the fixing device of the present invention is provided with a temperature sensor 20 which is a temperature detection means of the fixing solution as shown in FIG. The temperature detection means can be detected by bringing a detection means such as a thermocouple or thermistor into contact with the fixing solution. At this time, in order to directly measure the temperature of the fixing solution, the temperature can be detected by immersing the temperature sensor 20 in the liquid reservoir of the fixing solution supply unit as shown in FIG. As described above, the viscosity of the fixing liquid can be predicted by detecting the temperature of the fixing solution, and accordingly, the amount can be adjusted to an appropriate amount by the application amount adjusting means.

  However, it is the temperature of the fixing solution at the portion that regulates the amount of liquid that affects the applied amount, and may differ from the temperature of the fixing solution at the liquid reservoir. For example, in the fixing device as shown in FIG. 4, since the fixing roller 19-1 and the intermediate roller 19-5 slide, frictional heat is generated here. Due to this heat, the temperatures of the fixing roller 19-1, the application roller 19-2 and the intermediate roller 19-5 constituting the fixing device rise, so that the application roller 19-2 and the intermediate roller 19-5 for determining the application amount of the fixing liquid. There arises a situation in which the temperature of the fixing liquid at the nip portion differs from the temperature of the fixing liquid at the liquid reservoir. That is, the temperature of the fixing solution at the nip portion is higher, the viscosity is lowered, and the amount of fixing solution applied is reduced. Therefore, the temperature of the fixing solution estimated from the temperature of the fixing solution measured at the liquid reservoir is reduced. There is a difference between the applied amount and the applied amount of the fixing solution actually supplied. Therefore, in the fixing device of the present invention shown in FIG. 4, an intermediate roller that is an application amount adjusting unit is used to detect the temperature of the fixing solution in the application amount adjusting unit of the fixing solution supply unit that actually determines the application amount. A non-contact temperature sensor 21 for detecting the temperature of the surface of 19-5 is provided in the vicinity of the intermediate roller 19-5. In this portion, the fixing solution is a thin film on the order of μm, and the surface temperature of the intermediate roller or the like that transports the fixing solution is equal to the temperature of the fixing solution. Although the example of detecting the temperature of the intermediate roller has been described, a fixing roller or a coating roller may be used.

  Further, when detecting the temperature of the surface of the intermediate roller or the fixing roller, the contact type detection method may damage the roller surface. Therefore, a non-contact type detection means as shown in FIG. 4 is desirable. As this type of detection means, there is an infrared thermometer that converts the amount of infrared energy emitted from the surface of an object into a temperature using a thermopile. If such a non-contact type temperature detecting means is used, the temperature can be accurately detected without damaging the roller surface or the like.

  By appropriately controlling the fixing liquid application amount adjusting means in accordance with the detected temperature in this way, it is possible to prevent fluctuations in the application amount due to temperature. FIG. 8 is a characteristic diagram of the linear velocity ratio with respect to temperature. By controlling the linear velocity ratio of the intermediate roller to the fixing roller in the fixing liquid application unit of FIG. 4 as shown by the solid line in FIG. 8 (viscosity change correction with temperature), The amount of fixing solution applied can be made constant.

  By the way, it has been found that there is an optimum amount of fixing solution applied, but this optimum amount changes depending on the temperature. As shown in FIG. 9, the optimum amount decreases as the temperature increases, and the optimum amount is about 85% at 50 ° C. indicated by the dotted line with respect to the optimum amount at 30 ° C. indicated by the solid line. This is considered to be because the toner resin temperature rises and softens due to the rise in the fixing solution temperature, so that even a small amount of the fixing solution can be sufficiently softened. Therefore, if the amount of fixing solution applied is made constant as shown by the solid line in FIG. 8 (viscosity change correction with temperature), the fixing solution becomes excessive at a high temperature, which may cause a reduction in fixing speed. . Therefore, it is possible to always supply an optimal amount of the fixing solution by controlling the application amount of the fixing solution so that the application amount is decreased as the temperature rises.

  The broken line in FIG. 8 (viscosity change correction with temperature + necessary amount correction) is an example in which the linear speed ratio of the intermediate roller to the fixing roller is controlled in consideration of the decrease in the required amount due to this temperature. By doing so, an optimal amount of fixing solution can be applied at all times, so that a decrease in fixing property or speed due to temperature fluctuations can be prevented, and an image with always stable fixing quality can be obtained.

  Next, as a factor of temperature fluctuation of the apparatus, environmental fluctuation of the installation environment can be considered, but a factor occupied by a temperature rise due to machine operation in the apparatus is large. Therefore, in the fixing device of the present invention, the fixing liquid supply unit is provided with a cooling means. When the temperature inside the apparatus rises due to the operation of the apparatus, the cooling means can prevent the temperature of the fixing liquid of the fixing liquid applying apparatus from rising, thus preventing the viscosity of the fixing liquid from decreasing and the amount of application from being changed. be able to.

  The simplest cooling device is a method in which a heat-dissipating fin is installed to perform natural air cooling, but the cooling capacity is low, and this is not very useful when the temperature inside the device rises. Therefore, a forced air cooling method using a blower 22 as shown in FIG. 10 showing a first example of the cooling device may be used. At this time, cooling with outside air outside the apparatus using a duct or the like is effective in preventing the temperature of the fixing solution from increasing due to the increase in the internal temperature. Further, it is preferable that the blown air is applied to an intermediate roller or an application roller that determines the application amount of the fixing liquid.

  Further, instead of directly applying cold air to the roller surface, as shown in FIG. 11 showing a second example of the cooling device, for example, a heat pipe 23 is embedded inside the application roller 19-2, and a fin is attached to the extended portion. 24 may be provided, and cold air outside the apparatus may be applied to the fins 24 using the blower 22. In this way, it is possible to cool the roller uniformly and to prevent the transfer paper from being blown within the range through which the transfer paper passes and adversely affecting the transfer paper transfer. Furthermore, it is advantageous to take in air outside the machine.

  Even with a fixing device having such a cooling means, it is difficult to completely suppress the temperature fluctuation of the fixing solution. Therefore, the application amount adjusting means and the temperature detecting means are provided so that an appropriate supply amount is obtained according to the temperature. Adjust it. In this case, since the temperature fluctuation range is reduced by the cooling means, adjustment is possible even if the application amount adjustment capability is low.

  Furthermore, there is a liquid cooling method in which cooling is performed using a liquid in order to increase the cooling capacity. Compared with gas, a liquid has a large heat capacity and a high cooling capacity. Moreover, since the liquid which becomes a refrigerant | coolant can be easily transferred with piping, the heat exchange between external air can be performed by providing the radiator part for cooling outside the apparatus. In FIG. 12 showing a third example of the cooling device, the cooling liquid is allowed to pass through the coating roller 19-1, and the cooling liquid is circulated by the liquid feed pump 25. The cooling liquid is cooled by the outside air in the radiator 26 and is not easily affected by the temperature rise in the apparatus. Since this liquid can suppress the temperature rise of the application roller, it is possible to suppress the temperature change in the portion for measuring the application amount of the fixing liquid and to prevent the change in the application amount and the decrease due to temperature increase.

  Here, the temperature rise in the machine during operation is considered to be the main cause of the temperature fluctuation of the fixer, and the fixing device with a cooling mechanism has been described.For example, due to external factors such as cold districts, In use in a state where the temperature is low, it may be possible to form an image after the temperature has risen to some extent by separately providing a heater or heating the apparatus for a while without image formation.

Next, the softener contained in the fixing solution will be described.
The softening agent contained in the fixing liquid is a material that dissolves or swells the resin component constituting the toner. The softener is desirably a material that does not volatilize, that is, has no odor, and has an affinity for the carrier liquid constituting the liquid developer. Specific examples of the dissolving / swelling component include saturated aliphatic ester, aliphatic dicarboxylic acid ester, and aliphatic dicarboxylic acid dialkoxyalkyl.

Hereinafter, a saturated aliphatic ester that can be used as a softening agent will be described.
The saturated aliphatic ester is a compound represented by the general formula “R1COOR2”, R1 is an alkyl group having 11 to 14 carbon atoms, and R2 is an alkyl group having 1 to 3 carbon atoms.

  Examples of the aliphatic monocarboxylic acid ester that is a saturated aliphatic ester include ethyl laurate, ethyl tridecylate, isopropyl tridecylate, ethyl myristate, and isopropyl myristate. These have almost no volatilization and have affinity for synthetic oils such as silicone oil and PAO, mineral oils, hydrocarbon solvents, etc., and dissolve in dimethyl silicone, mineral oil, Isopar, etc. used as carrier liquids. The solubility in water is 0.1 g / 100 ml (25 ° C.) or less and is hardly soluble.

Furthermore, the aliphatic dicarboxylic acid ester which is a saturated aliphatic ester is a compound represented by the general formula “R3 (COOR4) ₂ ”, R3 is an alkylene group having 3 to 8 carbon atoms, and R4 is: An alkyl group having 2 to 5 carbon atoms.

  Examples of the aliphatic dicarboxylic acid ester include diisobutyl adipate, diisopropyl adipate, diethyl sebacate, dibutyl sebacate and the like. Most of these parts are hardly volatilized and are dissolved in synthetic oils such as silicone oil and PAO, mineral oils, and hydrocarbon solvents, and the solubility in water at 25 ° C is 0.1 g / 100 ml or less. It is poorly soluble.

The aliphatic dicarboxylic acid dialkoxyalkyl which is a saturated aliphatic ester is a compound represented by the general formula “R5 (COOR6-O-R7) ₂ ”, and R5 is an alkylene group having 2 to 8 carbon atoms. R6 is an alkylene group having 2 to 4 carbon atoms, and R7 is an alkyl group having 1 to 4 carbon atoms. Examples of the aliphatic dicarboxylic acid dialkoxyalkyl include diethoxyethyl succinate, dibutoxyethyl succinate, diethoxyethyl adipate, dibutoxyethyl adipate, diethoxyethyl sebacate and the like. Many of these parts as dialkoxyalkyl aliphatic dicarboxylates are hardly volatile (depending on the number of carbons). And the solubility in synthetic oils such as silicone oil and PAO, mineral oil, and hydrocarbon solvents is relatively low, and the solubility in water is higher than that of saturated aliphatic esters and aliphatic dicarboxylic acid esters. Therefore, when these are used as a softening agent, there is a method of emulsifying and dispersing in a synthetic oil such as silicone oil or PAO, mineral oil, or a hydrocarbon solvent with a surfactant having an HLB value of about 1 to 5. In any of the saturated aliphatic esters described above, the greater the number of carbons, the higher the viscosity and the higher the non-volatility. Further, odor can be reduced by refining, and some highly purified esters are almost odorless.

  The example of the softening agent mentioned above is a liquid softening agent. By using a liquid softening agent, compared with the case where the softening agent is a solid or gel, the carrier liquid can easily penetrate and contact with the toner is accelerated. Even if it is a liquid softening agent, the penetration rate depends on viscosity and surface energy, and a lower viscosity one has a faster penetration rate. Further, if the fixing agent is a liquid fixing solution, it can be easily supplied and can be supplied using a pipe or a pump. Handling is convenient because it does not fly like powder. Further, the amount of the thin layer formation can be easily regulated by using the fixing solution. Furthermore, if the fixing agent is in a liquid state, the contained softener is more likely to be mixed in the carrier liquid and in contact with the resin particles forming the toner as compared with the powder.

Next, a diluent for diluting the softener will be described. A non-volatile diluent is used as a diluent constituting the fixing solution.
If the dissolving / swelling component that softens the toner is supplied in a necessary amount or more with respect to the resin to be fixed, the dissolution of the resin proceeds so much that the flow of the toner to be fixed occurs. In addition, there is a problem that the curing of the resin is delayed and the time required for fixing becomes long. The resin forming the toner to be fixed is desirably in a semi-dissolved state or a swollen state, and depending on the type of the solubilizing / swelling component, it is sufficient that the solubilizing / swelling component is approximately half or less of the toner.

  It should be noted that a dissolving / swelling component that does not soften the toner unless it is supplied in half or more to the toner is not suitable because it is difficult to treat the dissolving / swelling component after the toner is softened. For example, the amount of toner constituting the toner image on the photoconductor, intermediate transfer roller, and transfer paper is several [μm] in thickness, and the dissolved / swelled component is supplied in a thinner and smaller amount. Is preferable.

  Further, it is desirable that the dissolving / swelling component be thin and a small amount can be supplied, but it is extremely difficult to uniformly supply the softening agent which is a small amount of the dissolving / swelling component. Therefore, as a method for supplying such a small amount of the dissolving / swelling component, a method of diluting the softening agent as the dissolving / swelling component with some liquid is generally used. As this dilution liquid, what uses water is known in consideration of the influence on the environment. However, since water tends to volatilize, the concentration of the water is likely to change, and there is also a problem of storage stability such as spoilage.

  Furthermore, when a diluent having good affinity with water mixed with water and easily soluble in water is used, water is easily adsorbed, so that moisture in the air is adsorbed and the concentration is likely to change. Furthermore, when the paper is supplied to the transfer paper P, there is a concern that the paper will cockle (become wrinkled). In addition, if a volatile diluent other than water is used, it will volatilize, causing problems of odor and air pollution.

  In order to solve these problems, silicone oil, mineral oil, etc. are mentioned as an example of the dilution liquid which does not volatilize, is hardly soluble in water, has almost no odor, and is diluted. Both have various structures and grades (viscosity / molecular weight). In the fixing device, a solution obtained by mixing 50% of the above-described softener and 50cSt or less of silicone oil as a diluent was mainly used as the fixing solution.

  If the softening agent is liquid, only the softening agent can be used as a fixing solution. However, the amount of resin on the transfer paper is extremely small, and it is difficult to supply an amount that does not become excessive. Accordingly, by diluting with an appropriate diluent and supplying it as a fixing solution, a necessary amount of a softening agent is contained in a supply amount of the fixing solution that can be stably supplied.

By the way, when diluting the softening agent that softens the colored particles to obtain a fixing solution, there are various types of the diluting solution, and the fixing device uses a non-volatile one as described above because of its good handleability. And avoids the use of water, which is the most harmless and common. The reason for not using this water is that its electrical resistance is low. For example, when diluted with a liquid having a low electric resistance such as water, the electric resistance of the fixing liquid is also low. In the fixing device, as described with reference to FIG. 1, when supplying the fixing liquid, the toner is transferred in order to prevent a phenomenon (offset) in which the colored particles (toner) adhere to the fixing roller. A fixing electric field that is pressed against the paper side is formed. The effect of the fixing electric field is influenced by the electric resistance of the fixing solution. For example, if a liquid having a low resistance such as water is contained, the potential difference between the roller surface and the fixing solution surface becomes small, and the effect of preventing the offset becomes scarce. . On the other hand, when it is a substantially insulator, it has a greater effect. Therefore, it is desirable that the fixing solution used in the fixing device has high electrical insulation, is substantially insulative, and has a volume resistivity of 10 ¹³ Ω · cm or more.

Examples of such highly electrically insulating liquids include silicone oil, normal paraffin, Isopar M (Exxon trademark), vegetable oil, and mineral oil used as a carrier liquid for dispersing resin particles of a liquid developer. Among these, silicone oil has a large intramolecular bond energy and is difficult to break, so it is resistant to heat, highly stable, and has high electrical insulation (volume resistivity is × 10 ¹⁴ to × 10 ¹⁶ Ω · cm). It is suitable as a carrier liquid and is used as a carrier liquid for a liquid developer. Similarly, methylphenyl silicone can be used as a carrier liquid. Since methyl phenyl silicone has a phenyl group, it has a high refractive index and high compatibility with other organic components. Therefore, it improves blending stability and is suitable for production of a liquid developer by mixing with toner. Moreover, it has excellent temperature characteristics and is hardly oxidized even at 500 ° C. for 500 hours. Furthermore, fluorosilicone oil can also be used as a carrier liquid. Fluorosilicone oil has a fluoro group (CF3) in the structure, and has a dielectric constant larger than that of other silicone oils, which is 50 Hz. There are other modified silicone oils that are reactive to side chains and end groups.

In the fixing device of the present invention, an insulating liquid used for a carrier liquid of a liquid developer is used as a diluting liquid constituting the fixing liquid. Specifically, non-volatile dimethyl silicone used as a carrier liquid for a liquid developer is used as a diluting solution for the fixing solution. Silicone has a large intramolecular bond energy and is hard to break, so it is resistant to heat and has high electrical insulation. In addition, silicone has particularly good wettability due to its low surface energy, and when used as a diluting solution for a fixing solution, the softener contained in the fixing solution can quickly reach the toner wrapped in the carrier solution. . Therefore, the time for softening the resin component of the toner with the fixing liquid can be shortened. Further, by using non-volatile dimethyl silicone as a diluting solution and a carrier solution for the fixing solution, there is no adverse effect on the environment. Dimethyl silicone has a volume resistivity of 10 ¹⁴ to 10 ¹⁶ Ω · cm and is suitable as a carrier liquid. Further, by using a non-volatile liquid, there is no need to provide a mechanism for recovering volatile components. Furthermore, when silicone oil is used as the diluent, the surface energy is low and the wettability is good. Therefore, when contact coating is performed with a fixing roller, a uniform and thin fixing liquid layer is formed on the roller surface. Easy.

  As an example of a diluent, silicone oil has a large atom-to-atom bond angle, a wide interval, and the surface tension is low because the molecules are spiral and the outer side is covered with methyl groups and the molecules attract each other. Low. Therefore, when applied to a lump of resin, it has good wettability and can be applied uniformly and thinly.

Moreover, in the case of dimethyl silicone as an example of silicone oil, for example, there is SH200 (trade name) manufactured by Toray Dow Corning Co., Ltd. According to the catalog value, if SH200-100cs (trade name) having a kinematic viscosity of 100 mm ² / s (25 ° C.), the volatile content at 150 ° C. (24 hours) is 0.5% or less and hardly volatilizes. Similarly, the volatile content of SH200-50cs (trade name) at 150 ° C. (24 hours) is 0.5% or less, which is desirable as a diluent. SH200-20cs (trade name) has a volatile content of 6% at 150 ° C. (24 hours), but the volatile content at room temperature is 120 hours when measured in a laboratory at a temperature of about 25 ° C. and a humidity of about 60%. However, since it was 0.1% or less, it can be used as a diluent. Dimethylsilicone is the most typical silicone oil and is characterized by colorless and transparent, tasteless and odorless, low surface tension, spreadability, chemical and thermal stability, moisture permeability, water repellency and non-volatility. Further, methylphenyl silicone has higher compatibility with other organic components in addition to the water repellency and lubricity inherent to silicone. The function of compatibilizing the dimethyl silicone oil with the organic oil / wax component also has the effect of improving the stability of the silicone oil blending, which is advantageous when using multiple dilutions.

  The carrier liquid adheres to the toner on the transfer paper to which the fixing liquid is applied. Therefore, when using, for example, water as a diluting solution for the dissolving / swelling component in the fixing solution, the carrier solution (dimethyl silicone, mineral oil, Isopar, etc.) of the liquid developer is generally an oil. The fixer is repelled. As a result, it takes time for the softening agent, which is a dissolving / swelling component of the fixing solution, to reach the toner, and it takes much time for the fixing solution to soften the resin particles of the toner. If a substance that is difficult to mix with the carrier liquid is used as the diluent, not limited to water, it takes time to soften the resin particles of the toner for the same reason.

  Therefore, the above-mentioned problem can be solved by using a diluent having affinity for the carrier liquid. Accordingly, the diluent and the carrier liquid are easily mixed, and the time until the softening agent in the fixing liquid reaches the resin particles of the toner in the liquid developer can be shortened, so that the fixing speed can be increased. .

  Further, as a solution for dissolving / swelling the softener, the same liquid as the carrier liquid of the liquid developer is used. By using the same material as the carrier liquid of the liquid developer as the diluent for the fixing liquid, the affinity between the fixing liquid and the carrier liquid is good, so the softener in the fixing liquid quickly contacts and penetrates the toner. Can be made. In addition, the resin component of the toner can be quickly softened.

  Further, by using the same substance as the carrier liquid of the liquid developer as the diluting liquid for the fixing liquid, even if a small amount of liquid developer is mixed in the fixing liquid, the function as the fixing liquid is not impaired. In addition, as described above, the carrier liquid of the liquid developer has high electrical insulation due to its necessity, and is suitable for use as a diluting liquid for the fixing liquid.

  As described above, by using a fixing solution having an affinity for the carrier liquid, the fixing speed can be increased, so that the image forming speed can be improved. In particular, by using the same material as the carrier liquid of the liquid developer as the fixing liquid, there is no change in the charging characteristics of the toner.

Here, as the carrier liquid of the liquid developer, Isopar (trade name) manufactured by Exxon Corporation, mineral oil, and PAO are listed. As for Isopar, for example, Isopar V is volatile at 25 ° C. (normal temperature and normal pressure: 25 ° C., 1 atm), left overnight, 2% or less, volume resistivity is 1 × 10 ¹³ Ω · cm, non-volatile It can be used as a sex carrier liquid. PAO is poly α olefin obtained by polymerizing α olefin. This is an oil that has long been used as a base oil for chemically synthesized oils. A poly α-olefin having 10 carbon atoms is often used because of its excellent viscosity index and pour point. This can be obtained by decomposing mineral oil, but a method obtained by polymerizing ethylene is general because it can be obtained efficiently at low cost.

  Further, when the fixing solution used in the fixing device of the present invention is non-volatile, the fixing solution softens the resin, and some of the fixing solution is taken into the resin layer, but most of the resin is discharged from the resin layer. It is believed that the layer solidifies. Therefore, when applying to a medium that absorbs the fixing solution such as transfer paper, it is difficult to recover the excess fixing solution after the application.

  Furthermore, when the fixing solution is non-volatile, the fixing solution will not expire without recovery. Therefore, when coating on a medium on which resin is fixed, such as transfer paper, it is preferable that the amount of the fixing liquid applied is an amount that can be held on the medium on which resin is fixed. For example, when the toner layer on the transfer paper is fixed, the amount of the fixing liquid may be less than the amount that the transfer paper can absorb the fixing liquid, although the amount varies depending on the oil absorption and thickness of the transfer paper. For this purpose, depending on the ability to dissolve and swell the resin of the softener, when the softener is diluted and used as a fixing solution, the ratio is changed to include sufficient softener to dissolve and swell the resin. In addition, the amount of the fixing solution is adjusted so as not to be too large. If the amount of the fixing solution is less than that which can be absorbed by the transfer paper, a mechanism for recovering excess liquid after dissolving and swelling the resin is not necessary. If the fixing solution is too much, the resin does not solidify even after the resin is dissolved and swollen, so that the resin may not be fixed and may be rubbed or spread when rubbed.

Next, an example of a fixing solution used in the fixing device will be described.
With the image forming apparatus shown in FIG. 1, the solid black image after fixing was evaluated by the smear test method described below. The term “nonvolatile” as used herein means that the amount of weight loss after 48 hours at room temperature (20 to 25 ° C.) and normal pressure is 2% or less.

Smear test method:
At the tip of the clock meter, an elastic material with a thickness of 5 mm is attached as a cushioning material, and a cloth is put on the elastic material. The density (three-point average) on the cloth after rubbing 10 times on the solid image is measured (Dcrk), and the value obtained by subtracting the cloth density (Dcls) from this Dcrk is divided by the original image density (Dinit). Let (Dsmr) be the evaluation value in the smear method. The smaller the value of Dsmr, the better the fixing property, and the current target value is 0.2 or less. The evaluation value Dsmr is obtained from the following equation.

  Dsmr = (Dcrk−Dcls) / Dinit

  The fixer shown below is substantially insulative and can use an offset electric field.

Next, a specific example of the fixing solution used in the fixing device of the present invention will be described.
<Specific example 1>
In this specific example, a fixer formulation having good affinity with the liquid developer is employed.
・ Diisopropyl adipate (softener, LD50 = 5g / kg)
10 wt%
Dimethylsiloxane (50 mPa · s, diluted solution, LD50 = 15 g / kg)
90 wt%

  In the image forming apparatus shown in FIG. 1, when the above fixing solution was supplied with a fixing device of 400 mg / A4 and evaluated by a smear test, the time required to satisfy the smear target value was 2 minutes after coating. It was. Moreover, the weight loss of the volatile matter measurement was 1% or less, and no odor was felt at all.

<Specific example 2>
In this specific example, a fixer formulation having good affinity with the liquid developer is employed.
・ Diisobutyl adipate (softener, LD50 = 12.3 g / kg)
50 wt%
Dimethylsiloxane (50 mPa · s, diluted solution, LD50 = 15 g / kg)
50 wt%

  In the image forming apparatus shown in FIG. 1, when the fixing solution was applied with a fixing device of 75 mg / A4 and evaluated by a smear test, the time required to satisfy the smear target value was within 1 minute. . And the evaluation result within 1 minute after application | coating was able to obtain the outstanding fixing property with 0.05. Moreover, the weight loss of the volatile matter measurement was 1% or less, and no odor was felt at all.

<Specific example 3>
In this specific example, a fixer formulation having good affinity with the liquid developer is employed.
・ Diisobutyl adipate (softener, LD50 = 12.3 g / kg)
50 wt%
・ Isopar V (14.8 mPa · s, diluted solution)
50 wt%

  In the image forming apparatus shown in FIG. 1, when the fixing solution was applied with a fixing device with an adhesion amount of 65 mg / A4 and evaluated by a smear test, the time required to satisfy the smear target value was within one minute. It was. And the evaluation result within 1 minute after application | coating was able to obtain the outstanding fixing property with 0.6. Moreover, the weight loss of the volatile matter measurement was 1% or less, and no odor was felt at all.

<Specific Example 4>
In this specific example, a fixer formulation having good affinity with the liquid developer is employed.
・ Di-n-butyl sebacate (softener, LD50 = 14.9 g / kg)
20wt%
Dimethylsiloxane (50 mPa · s, diluted solution, LD50 = 15 g / kg)
80 wt%

  In the image forming apparatus shown in FIG. 1, when the fixing solution was applied with a fixing device at an amount of 200 mg / A4 and evaluated by a smear test, the time required to satisfy the smear target value was within 3 minutes. . Moreover, the weight loss of the volatile matter measurement was 1% or less, and no odor was felt at all.

<Specific Example 5>
In this specific example, a fixer formulation having good affinity with the liquid developer is employed.
・ Di-n-butyl sebacate (softener, LD50 = 14.9 g / kg)
100 wt%

  In the image forming apparatus shown in FIG. 1, when the fixing solution was applied with a fixing device of 45 mg / A4 and evaluated by a smear test, the time required to satisfy the smear target value was within 2 minutes. . Moreover, the weight loss of the volatile matter measurement was 1% or less, and no odor was felt at all.

  Here, an experiment was performed to compare the fixing performance with and without the correction of the supply amount of the fixing solution due to the temperature rise of the fixing device, using the fixing solution of Example 2 described above. As a result, the time required to satisfy the smear target value at a room temperature of 25 ° C. was 1 minute after fixing, but if the correction was not performed at 45 ° C., the smear value was satisfied even after 10 minutes after fixing. I couldn't. However, by correcting the supply amount with respect to the temperature as shown in FIG. 8, a fixing quality equivalent to that at room temperature was obtained.

  Next, using the fixer of Example 2, an experiment was conducted to compare the fixing performance with and without the fixing device being cooled. As a result, the time required to satisfy the smear target value at room temperature of 25 ° C. was 1 minute after fixing, but when operated continuously for 30 minutes without cooling, the fixer temperature is 45. The smear value could not be satisfied even after 10 minutes had passed after fixing. However, by cooling, the temperature rise was about 30 ° C., and fixing quality almost equal to room temperature was obtained.

  As described above, due to factors such as an increase in the temperature inside the machine during operation of the machine, the temperature of the fixing solution rises, and the supply amount changes due to the change in the viscosity of the fixing solution. On the other hand, it is possible to prevent the deterioration of the fixing performance by providing the fixing liquid supply amount adjusting means and the temperature detecting means and adjusting the supply amount according to the temperature detection result. A similar effect can be obtained by providing a cooling means to suppress the temperature rise of the apparatus.

  The present invention is not limited to the above-described embodiments, and it goes without saying that various modifications and substitutions are possible as long as they are described within the scope of the claims.

1 is a schematic configuration diagram illustrating a configuration of an image forming apparatus according to an exemplary embodiment of the present invention. 1 is a schematic cross-sectional view illustrating a configuration of a fixing device according to a first exemplary embodiment of the present invention. It is a top view which shows the structure of the application | coating roller of FIG. FIG. 4 is a schematic cross-sectional view illustrating a configuration of a fixing device according to a second exemplary embodiment of the present invention. FIG. 6 is a characteristic diagram showing the amount of fixing liquid deposited on a recording medium when the ratio between the linear speed of the intermediate roller and the linear speed of the fixing roller of the fixing device according to the present embodiment is changed. FIG. 6 is a characteristic diagram showing temperature dependence of the viscosity of the fixing solution. FIG. 6 is a characteristic diagram showing a change in the amount of fixing liquid applied with respect to temperature. It is a characteristic view of the linear velocity ratio with respect to temperature. It is a characteristic view which shows the change of a smear value with respect to the softener supply amount ratio in the case of 30 degreeC and 50 degreeC. It is a schematic sectional drawing which shows the 1st example of a cooling device. It is a schematic sectional drawing which shows the 2nd example of a cooling device. It is a schematic sectional drawing which shows the 3rd example of a cooling device.

Explanation of symbols

19; fixing device, 19-1; fixing roller, 19-2; coating roller,
19-3; pressure roller, 19-4; doctor blade,
19-5; intermediate roller, 20, 21; temperature sensor, 22; blower,
23; heat pipe, 24; fin, 25; liquid feed pump,
26; Radiator.

Claims (9)

Fixing solution applying means for applying a fixing solution containing, as a component, a softening agent having a property of softening the resin fine particles to an unfixed image formed by resin fine particles on a recording medium;
A fixing device comprising: a fixing liquid application amount adjusting unit that adjusts an application amount of the fixing liquid by the fixing liquid application unit.   A temperature detecting means for detecting the temperature of the fixing liquid is provided, and the fixing liquid adjusting means adjusts the amount of fixing liquid applied by the fixing liquid applying means according to the temperature of the fixing liquid detected by the temperature detecting means. The fixing device according to 1.   The fixing device according to claim 2, wherein the temperature detecting unit detects a surface temperature of the fixing liquid applying unit.   The fixing device according to claim 2, wherein the temperature detecting unit detects a surface temperature of the fixing liquid application amount adjusting unit.   The fixing device according to claim 2, wherein the temperature detection unit is a non-contact temperature detection unit.   The fixing device according to claim 1, further comprising a cooling unit that cools the fixing liquid applying unit.   The fixing device according to claim 6, wherein the cooling unit is a forced air cooling mechanism.   The fixing device according to claim 6, wherein the cooling unit is a liquid cooling mechanism.   An image forming apparatus comprising the fixing device according to claim 1.

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